I can headbutt just about any surface repeatedly, sometimes from a running start, without sustaining any sort of injury. I hit lots of things with my head that I'd wouldn't want to hit with even a wrapped fist. I been practicing this off-n-on since I was twelve years old, first as misguided suicide attempts (demons talking in my mind and occupying my body, they wanted me to kill. Today looking back I thank them, what didn't kill me made me stronger. Before then, I had been the skinny kid in terrible shape, paid no attention whatsoever to training and conditioning my body. I began exercising with weights, machines, calisthenics, isometrics, stretches, and mental conditioning thinking about killing every day, I finally started turning my Mind-Body into a Weapon. A different path than Charles Atlas took, but the one that worked for me.) then as "do-it-yerself behavior modification therapy gone horribly wrong" (Some years later, I worked out at a gym where there were a lot of attractive women, and I wanted to condition myself to stop pestering them. So whenever I saw an attractive woman, instead of trying to strike up conversation I would slam my head repeatedly into a metal weight plate or some such. It went horribly wrong when I realized that I actually ENJOYED slamming my head into things as much or more than my lust for attractive women. I mean, I didn't get any kind of sexual high out of headbutting, I'm not some kind of deviant pervert. Well, I probably am many kinds of deviant pervert but just not that kind!!), finally now I am practicing my headbutting as the Extremely Dubious Ancient Jewish headbutt-based Martial Art of Barakodkod, which I learned from demon teachers, just as it was learned by the Bagatoor (Khazar Hunter-Warrior) in ancient times from the angels/demons encountered and fought on a Vision Quest.