On-computer and off-computer time are equally (un)productive. I like to spend a long time thinking about a problem without writing any code, then get it all out

On-computer and off-computer time are equally (un)productive. I like to spend a long time thinking about a problem without writing any code, then get it all out in one go as a foundation to build on; something like the Feynman Algorithm. And time spent socialising is only wasted if you don’t make the most of it. Like you said, it’s important to enjoy yourself and maintain a good work–life balance—otherwise you’ll just be unproductive and depressed.