One of my closest male friends in college was a cutter. Little slices all up and down his arms.

For me it was punching brick walls until my knuckles looked like raw hamburger. All through HS and college. I am paying for it now with seriously stiff knuckles.

I have also done a lot to my self "accidentally". I put it in quotes because it's hard to know how much was really accidental, how much was recklessness, and how much was intentional.