At the age of 18 I got the idea to learn every piece of knowledge in the world. At 25 I figured maybe I could master two or three fields. Starting from 30 I thought I could focus on two hobbies. Now I think I can keep at most one hobby and work on it a couple of times per week.

Key take: focus on what you really really enjoy (if you are not obssessed to it like water or air for 50% of the days then it's at most a hobby and you can drop the priority). And don't have kids. Kids are big time and energy sinkers. You get a kid and you can kiss goodbye to a lot of your old buddies.