“Life moves pretty fast. If you don’t stop and look around once in a while, you could miss it.” — Ferris Bueller, 1986
Ferris Bueller understood something that most retirement planners don’t.
In this choice movie, Ferris Bueller’s Day Off, all of the adults thought Ferris was reckless, and irresponsible. But Ferris understood at seventeen that certain windows are finite. The ability to stand on a float in the middle of Chicago and lip-sync “Twist and Shout” while the whole city dances doesn’t stay open forever.
DIY Retirees: your go-go years have an expiration date. Ferris knew it. Cameron didn’t.
Most retirement planning treats spending like Cameron treats that day — something to be managed, minimized, and survived rather than actually lived. The standard approach to retirement assumes your expenses are flat, inflation-adjusted, and consistent from the day you retire until the day you die.
Can anyone name what kind of retirement math this is?
“Anyone? Anyone?
…Voodoo Economics”
What Is the Retirement Smile?
Researchers who study actual retiree spending — not projections, but what people actually spend — have consistently found the same pattern. Graphically, it looks like a “smile.”
The Go-Go Years — early retirement, while you’re healthy and mobile. Travel. Experiences. Helping adult children. Finally doing the things you spent forty years saying you’d do when you had time. Spending is higher in these years, often significantly higher than people plan for. This is Ferris’s day in Chicago. The window is open. The city is dancing.
The Slow-Go Years — the middle phase, when the pace naturally slows. The big trips get shorter. The bucket list gets smaller. Spending declines — not because of financial pressure, but because of energy and inclination. This is Cameron sitting by the pool, watching the mileage tick up, not quite sure what to do with himself.
The No-Go Years — late retirement, when mobility fades and healthcare costs increase. Spending spikes again, often sharply, driven by medical costs, long-term care, in-home assistance, and the infrastructure of aging. This is the Ferrari going through the window.
Cameron’s father loved that car more than anything. He never drove it. He never let anyone near it. He preserved it perfectly for years, keeping it pristine on a pedestal in a glass garage, too precious to touch.
And it went through the window anyway.
The retirees who spend their go-go years hoarding savings out of fear — who skip the trip, skip the experience, skip the version of retirement they actually wanted — don’t avoid the late-life healthcare costs.
The Ferrari goes through the window whether you drove it or not. The only question is whether you got to enjoy it first.
Why the 4% Rule Misses the Smile
The 4% rule — the most widely used retirement planning benchmark — assumes flat, inflation-adjusted spending every year for thirty years. Same amount in year one as in year twenty. Same amount in the go-go years as in the no-go years.
Principal Ed Rooney spent the entire film trying to impose his rigid framework on a situation that didn’t fit it. He had rules. He had systems. He was absolutely certain he was right. And he ended up face-down on the Bueller family lawn while the day moved on without him.
That’s Principal Rooney. The 4% rule guy.
It’s not wrong, exactly. As a starting point, as a stress-test benchmark, as a rough guide to whether your plan is in the right ballpark — it’s useful.
The problem is that a flat withdrawal rate applied rigidly ignores the “shape” of your actual spending. It treats the go-go years the same as the no-go years. Studies show spending typically declines about 20% between your early and mid-retirement years — but that decline doesn’t account for the no-go years spike driven by healthcare and long-term care. The smile isn’t symmetrical. The right side can be steeper than the left.
If you model a flat 4% withdrawal against those actual spending curves, you’ll either underspend in the go-go years — missing the window Ferris was trying to show Cameron — or run short in the no-go years when the Ferrari goes through the window.
Cameron’s Problem
According to a 2026 EBRI study, about a third of retirees still have 100% or more of their initial savings remaining by their mid-80s. A Prudential Financial study found that married retirees with at least $100,000 in assets withdrew an average of just 2.1% per year — roughly half the recommended rate.
Cameron’s father preserved that Ferrari for years. Never drove it. Kept it perfect. And Cameron, standing there looking at all that preservation, finally understood: his father loved the car more than he loved him. The hoarding wasn’t caution — it was fear masquerading as responsibility.
The retirees who underspend in their go-go years aren’t being prudent. They’re being Cameron. They’re standing by the pool, watching the mileage tick up, not taking the day that’s right in front of them.
“Life moves pretty fast. If you don’t stop and look around once in a while, you could miss it.”
Bueller… Bueller…
Model the smile, not the flat line.
A good retirement plan accounts for the actual shape of your spending — higher in the go-go years, lower in the slow-go years, higher again in the no-go years for healthcare. It doesn’t assume you’ll spend exactly the same amount at 62 as you will at 82.
A Monte Carlo simulation that incorporates variable spending — the retirement smile — gives you a more honest picture of your plan than any flat-rate rule of thumb. Run 2,000 scenarios against your actual numbers, with spending that reflects how you’ll really live, and the probability distribution that comes out tells you something closer to reality.
You don’t have to skip the trip. You don’t have to preserve the Ferrari on a pedestal while life moves past the window.
You just have to model it correctly.
Run your free retirement probability simulation — variable spending included, no signup required.
You’re still here? It’s over. Go home.
At the end of the film, Cameron has an epiphany. Standing there, looking at the empty space where the Ferrari had been, he finally decides to stop being afraid of his father and start living his own life.
“I’m going to do something about it.”
That’s Cameron’s moment. Not the Ferrari going through the window — that was the no-go year healthcare bill arriving whether he was ready or not. The epiphany is the decision to stop hoarding the day and start living it.
The go-go window is open right now.
Don’t be Cameron.
Save Ferris.
Want to model the retirement smile against your actual numbers? The DIY Retiree Retirement Probability Calculator runs 2,000 scenarios with variable spending built in. Free. No signup.
Tony Markey, MBA, founded DIY Retiree to provide free retirement planning tools and straight-talk guidance for pre-retirees managing their own financial futures. Read more about his story here