there's a saying that goes neither travel nor triathlons get better with age. My inlaws (68 and 69) saved a bunch of money and retired about 6 or 7 years ago. they just came to visit us in France and had a really hard time getting around. My wife and I noticed it, the kids noticed it. Lots of sitting, breaks, waking up late, easily fatigued etc. My father in law wasted prime years in his early 60s waiting on a severance buyout that never happened, vesting options that were a tiny fraction of his NW and all the while endured a torturous and much younger boss so he could continue collecting his paycheck despite already being FI. OYS is one more year of working, sure, but more importantly its one more year of not doing something else extremely meaningful, new, fun and adventurous.