The Stoics had a phrase I’ve always found clarifying: memento mori—remember that you must die.

Morbid? Maybe. But it forces a useful FIRE question: What if you planned backward from the end of your life instead of saving toward a fuzzy future?

Assume you’re 40, expect to live to 95, and plan to spend $80,000 a year in retirement. At a 5% real return, about $5,000 saved today can fund your 95th year. Your 94th costs around $5,400. Your 93rd, about $5,700. Each year closer to today costs more because the money has less time to compound.

The traditional target doesn’t change. The 4% rule still points to a portfolio worth roughly 25 times your annual expenses. What changes is how you see the job: your earliest dollars fund your most distant years, and every contribution pulls the finish line closer.

Asset order matters too. Tax-advantaged accounts naturally fund later years. Stocks, real estate, and taxable holdings can cover earlier retirement years. I want bitcoin to have the longest runway because its asymmetric upside can pull more freedom into the present.

You aren’t stacking abstract wealth. You’re buying back years of your life.

See how to build your own reverse FIRE countdown: https://firebtc.io/p/working-backward-from-death