The other cutoff, 38, has a lot more play in it. One
reason I put it there is that I don't think many people
have the physical stamina much past that age. I used to
work till 2:00 or 3:00 AM every night, seven days a week.
I don't know if I could do that now.
Also, startups are a big risk financially. If you try
something that blows up and leaves you broke at 26, big
deal; a lot of 26 year olds are broke. By 38 you can't
take so many risks-- especially if you have kids.
Hmm, it's an interesting point. I'm not sure how well it holds up for the historical examples, though. Plenty of people (like Mozart) did lots of things early, but plenty also did lots of things later. Is one the predominant mode? I'm not sure, really. Some examples of people who did their most world-class work in their 40s or later: Descartes' famous works were ages 41-48; Newton's Principia was at age 44; Darwin's magnum opus was at 50; Pasteur discovered pasteurization in his 40s, and did his important work on vaccination in his 50s; Fleming discovered penicillin when he was 47. Of course, there are many examples besides Mozart who did most of their work in their 20s or 30s as well, so a bunch of examples don't really settle it in either direction.
That seems to imply that young people are so awesome that they can be more productive by working crazy long hours (compared to the standard 40 hours work-week).
Somehow, I doubt it. I understand his point, but when I see studies[1] that says that on average, working as little 60 hours a week is less efficient than 40 hours a week on the (not so) long term, I don't see how anyone can be more efficient by working even more than that. Even if they are still young and healthy. Even if they are driven like only messiahs have any right to be.
I'm pretty sure Sir Ranulph Fiennes says in one of his books that he preferred candidates for his expeditions who were in their 30s as he found them a lot mentally tougher than younger folks.
I suspect he knows a lot more about how people work under extremes of pressure than most.
