So, David Goggins - man is batshit crazy doing what he does. But that's it, he lives to overcome his own pain. He was on Andrew Huberman's podcast where it was mentioned that there is a region in the brain that gets stronger from doing things you don't enjoy - like actually loath it. Not that "it's painful but yadayada", actually hating every fiber in your body that is actaully engaged in the activity, and still doing it.
There's something profoundly human about that.