That's fair. I didn't relate that my friend went on to say that the reason math is a young man's game is that it's only the young who can read and memorize results fast enough, and keep enough of that information in their head at one time, to do important work at the frontiers of math. The brain has physical limits, just as the rest of the body does.

I am revolted by that idea. And I'm certainly a better coder than I was in my thirties, and I was better then than I was in my twenties. (Not that I'm under the illusion that my work compares to PhD-level math.)