I read code for fun sometimes, but it's usually not whole codebases. I like to read PRs that I think are exciting in projects that I use, and then branch out to the context that they're invoking or changing as well.

I've never thought of it as something I do to advance myself as a programmer, though. I just kinda do it on impulse, and I'd still do it even if I found out it didn't really improve my skills.

Anyone else recreationally browse PRs in F/OSS that they use, kinda like reading the news?