[neilv]

It really varies by person and circumstances, and there's also things you can do (analogous to when someone with aches starts lifting weights, and gets in the best shape of their life).

Late nights are often a bad idea anyway. Though I literally just finished a successful all-nighter about an hour ago, I try not to make a habit of it. And there's a ton of things we know how to do, so that most all-nighters never need to happen.

Regarding typing, it might not be a "this is my life now" thing you just have to accept and work with, but there might be some practice/nuance or environmental factor that you can change for big wins. You can look into typing/workstation ergonomics, and experiment with the many variables, to see what works for you. I had to do that in my late teens, when most of our development team on a stressful project developed hand pain and worse, and learned what worked for me. Now I can type all day and night without problem. Having that known-good baseline means that I soon know when I start doing something that doesn't work for me. (Last time was a few years ago, when I started using a laptop with a numeric keypad at a startup, and hand started hurting. I think probably because hands had to twist badly for the way I was balancing the laptop with the off-center main keyboard. So I switched that work to a laptop without an off-center keyboard, and problem disappeared.)