Why do i enjoy pain so much?

even as a child, i enjoyed having pain in my mouth. when i was 6 i had all my baby teeth ripped out by myself. even now at 18 i still like spacing my teeth out with tooth picks or string until my head gets numb from the pain. i have perfect teeth though. (my dentist loves them, =D ) i had fun getting my wisdom teeth removed and even waited until they were all grown in because i liked the feeling. but why do i enjoy this pain?could this be a little issue behind a big mental problem? i enjoy sports injuries as well. i love getting hurt, and then pursue forward even though i'm injured. for instance, if when running, i fall and scrape my shoulder and bruise my leg, i like to get up as fast as possible and continue. i like fighting too! i also have a high pain tolerance. could i be a masochist? i do fantasies about forceful men, even though i practiced androgyny. whats wrong with me? could this only be part of an issue i have? thanks in advance