I've never done any kind of straight up self-mutilation. However, I was part of a sort of "fight-club" in high school. We'd fuck each other up pretty badly, but the rush it gave me seemed worth it. I would also punch hard surfaces a lot. Technically it was for training, the calcium deposits in the micro-fractures you create make your knuckles like brick, but I'd be lying if I said the pain wasn't cathartic.