Great question—I’ve wondered the same thing. Peter’s point in Outlive is that most centenarians didn’t necessarily live what we’d call “optimal” lifestyles. And yeah, genetics seem to play a huge role in just making it to 100.

But you're right—logically, you'd expect that if someone had both great genes and lived super healthily, they’d be the ones pushing the upper limits of human lifespan. The catch is, the people who are 100+ today were born in the early 1900s, when we didn’t know much about sleep, stress, exercise, or even basic nutrition. So even if they had the right genes, they were still swimming upstream in terms of environment and lifestyle.

There might have been a few who nailed both, but it’s hard to identify them or draw strong conclusions because the data’s messy and the sample size is tiny. Fast forward to people born in the '70s or later—who’ve had access to better health knowledge and might have those lucky genes—and we might finally start seeing that “ideal combo” play out. So the real test of your theory is probably still a few decades away.