That's basically my lifelong addiction.

I have dozens of projects that I will obsess over for a few weeks. When I was younger I would convince myself that what I was doing would change the world and I was going to make billions of dollars, but eventually I became more honest with myself: I do these projects because I want to learn about <<subject X>>.

I built a Icecast server recently because I wanted to learn more about audio encoding and streaming protocols. I built a clone of fzf because I wanted to learn more about Rust and diffing algorithms. I wrote a custom async scheduling framework for my Swaybar because I wanted to learn more about how async scheduling works. I started trying to prove the Collatz conjecture because I wanted to learn more about Isabelle.

I am ok with this being part of my life; I like learning new bits of math and technology, and the easiest way to actually learn a new concept (instead of nodding along in a book) is to try and do something with that knowledge. I think "learning for fun" is far from the worst hobbies one could have.