Finding limits

Well, that's what you do in Analysis, you find limits of sequences, like the limit as n goes to infinity of 1/n is zero.

I'm also finding my own limits. Seems that I can practice pretty much all day long, but if I'm actually learning something (or refreshing from 30 years ago), about 6 hours a day is as much as my brain will take. I seem to recall that was about what it was in my 20's, too. I could code or do homework for hours on end if needed, but intake of new information, whether reading or in lecture was capped at around 6 hours.

It's interesting (to me, anyway), that that's also the physical limit for most elite athletes (runners are a significant exception as the weight-bearing nature of the sport knocks them down to 2-3 hours per day). That could be coincidence, but I wonder if it's actually a genetic adaptation of some sort. Like, we're just meant to truly expand ourselves no more than six hours a day because that's enough. After that, you're better off honing the skills you already have.