I could just be further down the path due to lucky opportunities. 20 years ago I had no ambitions beyond game programming. It was only when I got a biology-related job that learning in my free time started displacing mindless entertainment. The whole field is one big nerd snipe - there are endless opportunities where you can advance the frontier of knowledge by combining a few existing ideas and working out the kinks. The more you read, the more opportunities you see. It's thrilling. I don't think I can go back to non-science work.

I think the dopamine from constant learning also helps to keep my ADHD in check. If I start the weekend with some study, I'll usually also get the housework done. If I start with a video game or TV show, I'll probably spend the rest of the weekend stressing about my todo list and not getting anything done.