> Looking at how other people describe their experience, it seems like the figuring out part brings them joy

It's the pleasure of mastery. To me, the fun of a challenge like that is in gradually mastering something difficult and then being able to perform it perfectly. In fact, I'm sometimes a bit disappointed by the way that a boss fight ends when you get it right. The feeling of getting it right is my reward for the work I've put in, and I want that feeling to be drawn out. This is why I don't mind dying and restarting, at least in a good boss fight. The experience of being in the fight feels good and only gets better. That's why these games are rewarding to replay. It's like you're playing the hits or something.

My favourite boss fights are from Sekiro—there's a nice little video about it here¹ if you're interested in what other people love so much about tough boss fights.

[1]: https://www.youtube.com/watch?v=7W4li9yfY3o

The video moved something in me. I feel I hate being put down a bit too much. (Being made feel stupid, small, inadequate). I mostly counter this not by facing the problem itself, but by overpowering myself in another context - in games, via gear or levels. After winning these battles I don't feel victorious, I feel like I finally got away.

Thanks for sharing your perspective, I really appreciate it.