How to Design a Fulfilling 100-Year Life
Why the Old Work-Retire Model Is Broken—and What to Do Instead
Have you ever really thought about what it means to live to 100?
Not in some sci-fi, futuristic sense. But in a real, personal way—waking up and realizing you might still have 30 or even 40 years left after you retire. That’s an entire second adulthood. Enough time to go broke twice, start three new careers… or watch your grandkids have grandkids.
Living longer sounds like a blessing. And in many ways, it is.
But here’s the twist:
Living longer—something we all instinctively want—could actually backfire if we don’t radically rethink how we approach life.
That’s the bold argument behind The 100-Year Life by economist Andrew J. Scott and business professor Lynda Gratton. It’s not a book about kale smoothies or longevity hacks. It’s about life design—how to reimagine your future when age 100 becomes a likely reality, not a lucky one.
One stat jumps out early in the book:
“More than half the babies born in developed countries since 2007 are expected to live to over 100.”
That’s not a prediction. That’s already happening.
Yet most of us still plan our lives based on outdated assumptions: retire at 65, then coast. But if you're going to live to 95—or longer—that model breaks. Financially, emotionally, and socially.
As the authors put it:
“The model of a three-stage life—education, work and retirement—was never designed to cope with lives that might be 100 years long.”
And yet we’re still trying to live that life. Like we’re updating 21st-century software on a 20th-century operating system—and wondering why it crashes.
This blog post will unpack what The 100-Year Life teaches us about how to thrive in this new world. We'll look at:
Why the three-stage life is obsolete
What the future of multi-stage living looks like
How to build intangible assets like health, relationships, and reinvention
Why money alone won’t be enough—and what to do instead
Because this book isn’t about surviving longer. It’s about living better across time—with meaning, purpose, and momentum.
Let’s dive in.
The Death of the 3-Stage Life
For most of the 20th century, life followed a predictable script:
Get educated in your teens and early 20s
Work full-time for 40+ years
Retire around 60 or 65
It was neat. It was simple. It fit the math.
But that model wasn’t designed for long lives. It was built for a world where people lived to 70—not 90 or 100.
As The 100-Year Life points out:
“The three-stage life was a brilliant social invention. But it simply cannot work when everyone is living for 100 years.”
Think about that. If you retire at 65 and live until 95, that’s 30 years without earned income. A second adulthood… with no playbook.
Why the Old Model No Longer Works
In the book, Gratton and Scott explain that if you want to maintain your current lifestyle in retirement and live to 100, you’d need to save over 25% of your income every single year of your working life.
Almost no one is doing that.
And retirement itself—this sharp “stop working” moment at 65—just doesn’t make sense anymore, especially when people are staying healthier and more capable into their 70s and 80s.
The traditional model leads to a few serious problems:
Burnout during the work phase (because it’s your only chance to earn)
Identity loss during retirement (especially if you love your work)
Loneliness and stagnation in what could be vibrant decades of life
We Need a New Mental Model
Psychologist Erik Erikson famously described eight life stages—but in a 100-year life, we might need nine or ten.
Life is no longer a straight line. It’s a series of reinventions.
As the authors write:
“We are trying to compress a long and complex life into a system that was designed for shorter, simpler ones.”
The implication? We need to design new ways to live, work, and grow across time—not just tack on extra years to the end.
In the next section, we’ll meet three characters—Jack, Jane, and Jimmy—each born in a different era, each facing the 100-year life in radically different ways.
They’ll help us see just how much the game has changed… and what might be coming next.
Jack, Jane, and Jimmy: Three Futures
To truly grasp how the 100-year life reshapes everything, The 100-Year Life introduces us to three fictional characters—Jack, Jane, and Jimmy.
Each was born in a different decade. Each faces different expectations and realities. Together, they show how living longer creates both challenges and opportunities, depending on when you were born—and how you respond.
Jack: The Three-Stage Life, Fully Intact
Jack was born in 1945. He represents the classic model—education in his early 20s, a lifelong career with a stable employer, retirement around 65, and a comfortable few decades afterward.
He benefited from strong pensions, rising property values, and a booming postwar economy. His life follows the script nearly perfectly.
But Jack’s experience is increasingly rare.
He’s part of a transitional generation—among the last to fully live out the three-stage life without serious financial or social disruption.
Jane: The Life Caught in Transition
Jane, born in 1971, thought she could follow Jack’s path. But her reality looks different.
She entered a more volatile job market, faced career disruptions, and saw pensions disappear. Her house may not have appreciated the way Jack’s did. She may have paused her career to care for kids or aging parents—and returning to the workforce wasn’t as simple as expected.
Jane realizes in her 50s that retirement at 65 is unrealistic. She hasn’t saved enough. But she’s also not ready to stop working. She begins exploring new possibilities: going back to school, shifting careers, or starting something new later in life.
The authors sum up her challenge well:
“Jane’s challenge is that she has to compress a long and complex life into a system that was designed for shorter, simpler ones.”
Jane is adapting, but she’s doing it mid-flight.
Jimmy: Designing the Multi-Stage Life from Day One
Then there’s Jimmy, born in 1998. He’s grown up in a world where job security is rare, retirement feels abstract, and reinvention is expected.
Jimmy doesn’t even pretend to follow the three-stage model. Instead, he’s preparing for multiple careers and identity shifts.
He might freelance in his 20s, launch a company in his 30s, shift to public service in his 40s, and teach part-time in his 70s. To him, flexibility isn’t a luxury—it’s a survival skill.
Gratton and Scott explain:
“He must design a life that fits a world where age and stage are no longer tightly correlated.”
In Jimmy’s world, age is no longer destiny. There’s no linear progression. There’s just life, unfolding in stages that he’ll have to navigate and shape himself.
Why This Matters
Most of us are somewhere between Jane and Jimmy.
We were raised with Jack’s assumptions—but are now facing a future more like Jimmy’s. That’s a tough transition to make without a map.
But the good news is: it’s possible to design a new map.
In the next section, we’ll explore what that map might actually look like. What does a multi-stage life really involve? What are the stages, and how do you move between them?
Let’s dig into that next.
What a Multi-Stage Life Looks Like
If the old three-stage life is breaking down, what replaces it?
According to The 100-Year Life, we’re entering a world of multi-stage lives. Not linear. Not fixed. But flexible, dynamic, and deeply personal.
Instead of following the same path as everyone else, your life becomes a sequence of distinct stages—each one shaped by your goals, opportunities, health, and finances.
Think of it not as a ladder, but a modular structure. Here’s what some of those modules might look like.
Education – Not Once, but Repeatedly
In the traditional model, you front-load education in your teens and early 20s. In a 100-year life, that’s no longer enough.
Your skills will age faster than your body.
The authors explain:
“Education will become a recurring stage, not a one-off event.”
This means going back to school—or re-skilling online—at 35, 50, even 70. Whether it’s through bootcamps, certifications, or informal learning, staying current will be essential not just for employment, but for relevance and reinvention.
Bill Burnett and Dave Evans, authors of Designing Your Life, put it another way:
You are not one fixed identity. You evolve. And you’ll need to keep learning to support that evolution.
Multiple Careers – Not Just One Track
In a multi-stage life, one career path won’t be enough.
You may start in marketing, shift into education, launch a nonprofit in midlife, and then coach or consult later on.
Gratton and Scott write:
“A long life makes it likely that people will have at least two or three distinct careers.”
David Epstein’s book Range reinforces this. The future belongs to people who can pivot across domains, transfer knowledge, and see patterns others miss. Generalists—not specialists—will thrive in this environment.
Exploration – Space to Wander, Try, and Reset
One of the most exciting concepts in the book is the explorer phase.
Rather than racing from school to work, you might take time in your 20s (or later) to try different paths. Travel, apprentice, test out multiple roles. In a longer life, this isn’t indulgent—it’s strategic.
The startup mindset—test, learn, iterate—applies to life, too.
As Reid Hoffman says in The Start-Up of You, we should live in “permanent beta,” always evolving, never final.
Transition – Reinvention as a Life Skill
Life isn’t just about building—it’s about reinventing.
Midlife transitions are becoming normal: career breaks, sabbaticals, re-skilling, caregiving shifts. These periods don’t signal failure. They’re part of a well-lived 100-year life.
The authors introduce a key concept here:
“Transformational assets”—your ability to reframe your identity, absorb uncertainty, and move forward.
Transitions require more than a résumé update. They require emotional resilience, curiosity, and a capacity to see yourself anew.
Portfolio Careers – A New Kind of Retirement
Many people in their 60s and 70s won’t want—or need—a full-time job. But they’ll still want to contribute.
That’s where portfolio living comes in: part-time work, mentoring, volunteering, and creative projects all woven together.
This phase balances structure with freedom, impact with ease. It’s not retirement—it’s rebalancing.
A Life with No One Right Order
Here’s the most important insight: these stages aren’t universal, and they aren’t sequential.
Some people will explore early. Others will reinvent at 60. Some will build a portfolio career in their 40s. There’s no blueprint.
“The sequence and timing of these stages will become more personalized and fluid.”
Your job is to sketch your own path—and adapt as life unfolds.
So how do you thrive in a life this fluid?
It turns out, the most powerful assets aren’t financial. They’re personal and social. In the next section, we’ll talk about intangible assets—and why your health, relationships, and capacity to reinvent may matter more than your bank balance.
The Rise of Intangible Assets
If you’re planning to live to 90 or 100, you probably worry about money. That’s fair. But money alone won’t get you there—not well, anyway.
In The 100-Year Life, Lynda Gratton and Andrew Scott introduce a crucial concept: intangible assets.
These are things that don’t show up on your bank statement, but may ultimately matter more than any savings account. They’re the assets that help you earn, adapt, stay healthy, and stay connected—across every stage of life.
The authors categorize intangible assets into three types.
Productive Assets: Your Ability to Earn
These include your skills, knowledge, work experience, professional network, and reputation. In a long life, your capacity to earn can’t depend on what you learned at age 22.
The world changes. Industries evolve. Technology transforms.
“The half-life of skills is decreasing. What you know today may be obsolete in ten years.”
The implication is simple: you must reinvest in yourself continually. That might mean new certifications, courses, mentors, or side projects. Your résumé becomes a living document—updated not every few years, but continuously.
Vitality Assets: Your Health and Energy
Vitality assets include your physical health, emotional resilience, and close relationships. These aren’t luxuries. They’re survival tools.
One of the biggest risks in a long life is that you arrive at your later decades physically depleted and socially isolated. Gratton and Scott put it bluntly:
“Poor health, loneliness and social isolation can destroy the benefits of a long life.”
In other words, if you’re not protecting your energy and nurturing your connections, your later years won’t be fulfilling—no matter how much money you’ve saved.
Think of your vitality like compound interest. The benefits (or costs) of your daily decisions—sleep, movement, stress management, social time—build up over decades.
Transformational Assets: Your Ability to Reinvent
These are your mental tools for handling life transitions.
Reinvention isn’t a one-time event. In a multi-stage life, you’ll face many moments where you’ll have to rethink who you are and what you do next: career changes, relocation, caregiving, empty nests, starting over.
“In a multi-stage life, transitions are normal. But they require agency, self-knowledge and narrative skills.”
This is about more than updating your LinkedIn. It’s about crafting a new internal story about who you are—and being flexible enough to live into it.
In Designing Your Life, Bill Burnett and Dave Evans describe it as prototyping your future. You try, test, adapt, and move forward. That mindset becomes a powerful advantage in a long life.
A Tale of Two 70-Year-Olds
Let’s make it concrete.
Imagine two people at 70.
One is financially stable but sedentary, socially isolated, and out of sync with today’s world. The other may have less money, but is healthy, connected, still learning, and working on something meaningful part-time.
Who’s better prepared for the next 25 years?
In a 100-year life, your emotional, physical, and intellectual assets matter as much as your financial ones. Maybe more.
And just like with money, you need to invest early and consistently in these intangible assets—because they compound over time.
Next, we’ll take a hard look at one institution most people still assume is fixed: retirement. In a 100-year life, it may need a complete redefinition.
Rethinking Retirement
If you ask most people what their long-term goal is, they’ll say something like: “I just want to retire comfortably.”
But here’s the problem: retirement, as we know it, was never designed for long lives. It’s a 20th-century invention that’s rapidly falling apart.
In The 100-Year Life, Gratton and Scott explain:
“The idea of a fixed retirement age is a historical construct—a product of 20th-century industrial models and outdated financial assumptions.”
And those assumptions? They’re collapsing under the weight of new realities.
The Original Retirement Model No Longer Fits
When retirement became common, life expectancy hovered around 70. Retiring at 65 meant enjoying perhaps a decade of leisure.
But today, many people will live to 90 or 100. That’s not 10 years of retirement. It’s 25 to 35 years.
A 35-year vacation might sound appealing—until you try to fund it.
To maintain your lifestyle across that long stretch, you’d need to save more than a quarter of your salary every year of your working life. And most people—across income levels—aren’t doing that.
“Longer lives demand a fundamental rethinking of how retirement is financed—and what it’s for.”
So what’s the alternative?
Retirement Isn’t the Goal. Rebalancing Is.
Gratton and Scott propose a more realistic, human-centered idea: phased transitions rather than a hard stop.
In this model, you don’t work at full intensity until 65 and then drop off a cliff. Instead, you create cycles of effort and recovery, spacing out mini-retirements, sabbaticals, caregiving breaks, and downshifts throughout your life.
This gives you space to:
Recharge in your 40s
Reinvent in your 50s
Stay active and useful into your 70s
This is where ideas from other books resonate.
In Die With Zero, Bill Perkins argues:
“Don’t save all your fun for the end. Spend your life energy wisely across your whole life.”
And in The 4-Hour Workweek, Tim Ferriss calls these breaks mini-retirements—intentional time off at multiple points in life, not just the end.
The common theme? Redesign your life around rhythm—not rigid endpoints.
The Power of Modularity
Instead of a single long “retirement,” your life might include:
Short breaks to care for family or recover from burnout
A pivot to lower-stress, more meaningful work in your 60s
A portfolio phase of part-time mentoring, teaching, and volunteering in your 70s
“A longer life doesn’t mean a longer retirement—it means a more creative distribution of work and leisure across time.”
This model is more flexible. More realistic. And, for many, more fulfilling.
Retirement as Reinvention
The point isn’t to eliminate retirement. It’s to change its purpose.
In the future, “retirement” won’t be about withdrawing from the world. It will be about reshaping your contribution in ways that match your energy, experience, and values.
So instead of asking, “When can I retire?”
Ask:
“How can I rebalance my time over a longer life?”
“What kinds of work will still energize me in my 60s and 70s?”
“How can I build in breaks along the way, instead of deferring all rest to the end?”
These are the questions of a 100-year life.
In the next section, we’ll look at what supports all of this—your relationships. Because as life stretches out, the strength of your social and emotional connections matters more than ever.
Relationships and Emotional Wealth
In conversations about longevity, people usually ask:
Will I have enough money?
Will I be healthy?
But here’s a third question—arguably just as important:
Will I have people I care about—and who care about me?
The 100-Year Life makes it clear:
“Emotional engagement with others becomes increasingly important as life extends… Relationships are a key part of building resilience and wellbeing across a multi-stage life.”
This isn’t just a feel-good insight. It’s backed by hard data.
The Longevity Study That Proves It
The Harvard Study of Adult Development, which tracked individuals for over 80 years, found that the strongest predictor of health and happiness in later life wasn’t wealth or status.
It was quality relationships.
As psychiatrist Robert Waldinger, who leads the study, put it:
“Good relationships keep us happier and healthier. Period.”
And in a 100-year life, this becomes even more important. Because more years = more transitions.
More career changes.
More family complexity.
More emotional shifts.
Your relationships will be tested, stretched, and—if neglected—lost.
The Old Relationship Model Is Breaking Too
Most personal relationships, like life stages, were built around the three-stage model:
You marry in your 20s or 30s, raise kids, and grow old together after retirement.
But what happens when retirement isn’t one clean phase? When one partner keeps working? When caregiving or reinvention creates new demands?
Gratton and Scott explain:
“Most personal relationships are still built around a three-stage life model… but longevity means these will need to be reimagined.”
This doesn’t mean relationships will fall apart. It means they must evolve.
People in their 60s may face 30 more years together—years where values, priorities, and health can shift dramatically.
Friendships and community must also be redefined. As people move more, change careers more, and live independently longer, intentional connection becomes essential.
Co-Creating Life with Others
A key concept in the book is co-creation.
In a long life, you’re not just designing your own journey—you’re shaping it with others.
That means:
Having honest conversations with partners about what each stage might look like
Supporting friends through transitions (and letting them support you)
Building community intentionally, especially when moving into new phases of life
Without this effort, isolation creeps in. And isolation, studies show, is as harmful to health as smoking or obesity.
“Intimacy and emotional support become survival tools—not just luxuries—in a 100-year life.”
Are You Investing in Emotional Wealth?
We often obsess over retirement savings, but rarely ask:
Am I investing in my relationships like I do my finances?
That might mean:
Making time for connection in your weekly routine
Talking with your partner not just about money, but about meaning
Making new friends in midlife (yes, it’s awkward—but critical)
Saying yes to the social invitation, even when it’s easier to stay home
Relationships are the most resilient, renewable source of wellbeing over time. But only if you nurture them.
Next, we’ll return to a tough but practical topic: money. Not just how to save more—but how to design a financial life that actually fits a longer, more flexible, and more human future.
Money and the Longevity Gap
Let’s be honest: when people hear “100-year life,” their first thought is often—
How am I going to afford that?
It’s a valid question. And The 100-Year Life doesn’t sugarcoat it.
“A long life is expensive. Working longer is inevitable for most people—not optional.”
But instead of panic, the book offers something more helpful: a reframing of how we think about work, saving, and spending across time.
The Math Is Changing
Traditional retirement models assume a 40-year career followed by 10–15 years of retirement.
But if you live to 95 or 100? Retirement could last 30+ years.
To make that work financially, you’d need to save more than 25% of your salary each year during your working life. That’s a high bar—and one most people, even high earners, don’t hit.
This is the longevity gap—the widening space between how long we live and how financially prepared we are to support those years.
And it’s not a niche issue. It affects middle-class professionals, entrepreneurs, gig workers, and retirees alike.
Working Longer—But Differently
Gratton and Scott argue that the solution isn’t just working more. It’s working differently.
Instead of the old model—work full-time until 65, then stop—we’ll need more flexible patterns:
Full-time work in early career
Downshifts, career changes, or sabbaticals in midlife
Part-time work, consulting, or mentoring in later life
This gives people time to rest, re-skill, or care for family without permanently exiting the workforce.
It also keeps income flowing longer, reduces reliance on retirement savings, and supports healthier aging.
“A longer life doesn’t mean a longer retirement—it means a more creative distribution of work and leisure across time.”
It’s Not Just About Saving—It’s About Timing
This is where Die With Zero by Bill Perkins offers a useful complement. Perkins argues that we often over-save and under-live, postponing joy until it’s too late.
“Your life energy is limited. The point of saving money is to spend it wisely—on time, memories, and meaning.”
In a 100-year life, you don’t want to wait until 70 to enjoy your health or your wealth.
Instead, financial planning should focus on matching money with moments. That might mean:
Taking a sabbatical at 40
Traveling more at 55
Rebalancing work and leisure gradually, not suddenly
Financial Flexibility Is the Goal
Rather than chasing a massive savings number, aim for:
Multiple income streams over time
Skills that keep you employable into later life
Lower fixed costs, to stay agile
Smart timing of major life events and expenses
And perhaps most important: a financial strategy that supports your life design, not just your “retirement.”
Because retirement is no longer the end. It’s just another phase—one of many in a long, evolving life.
So yes—money matters. But in a 100-year life, success isn’t about retiring rich. It’s about having enough flexibility and agency to shape a life that stays meaningful and sustainable across time.
Next, we’ll bring it all home with a final message: don’t drift. Design your life.
Final Message: Design, Don’t Drift
We’ve covered a lot.
We’ve seen how the old life model—school, work, retire—is no longer built to serve people who will live 90, 95, even 100 years. We’ve explored what a multi-stage life could look like. We’ve talked about health, money, reinvention, and relationships—not as side topics, but as core life assets.
But here’s the idea that ties it all together:
Don’t drift. Design.
In the past, it was easy to drift. Society had a script for you. The path was relatively fixed. Deviating from it felt risky.
But in a 100-year life, the script is gone.
If you don’t actively design your life, it’s easy to become lost—overworked, under-connected, stuck in outdated identities, or unprepared for what’s next.
As Gratton and Scott write:
“The 100-year life is not about adding extra years at the end—it’s about changing how we live now.”
That’s the real call to action.
Start Designing Today—Not Someday
Designing your life doesn’t mean having a 50-year plan. It means asking better questions more often:
What stage am I in?
What do I want this phase to look like?
Where am I investing—not just financially, but emotionally and intellectually?
What needs to be rebalanced?
It means treating your time like the precious resource it is—and your relationships, health, and learning like strategic assets.
Small Steps Count
You don’t have to change everything tomorrow. But you can:
Sketch out what your life might look like in 5 or 6 stages, not 3
Revisit your relationship with work and ask whether it’s sustainable
Reinvest in friendships or family dynamics that matter most
Begin building transformational assets—like adaptability, curiosity, and resilience
You have more time than past generations. The gift of a long life is real. But it only becomes a blessing if you take ownership of it.
“A long life is a gift. But it’s also a challenge. The earlier you prepare, the better the gift becomes.”
So start now. Not to add years at the end, but to add life at every stage.
Because the 100-year life isn’t just about survival. It’s about creating a life worth living—all the way through.