That's assuming that you value all years equally, which most people don't.

With good living (and good luck), I've seen people very active and happy through their 80s and 90s.

With bad living, I've seen some very unhappy and dead people in their 40s, 30s, or even 20s (Winehouse, Cobain, Joplin, Morrison, et al, of the Forever 27 Club). Frequently death preceded by more than a few years of lower productivity.

Of course, luck plays a part too. I've known a few people who woke up dead, suddenly or otherwise, at a young age for no particularly predictable exogenous cause. But that's still statistically a low probability and for some cases (particularly accidents and violence) largely avoidable with appropriate precautions.

Is that really true? I'm looking forward to pretty much every phase of my life (except the death part, I could happily skip that).