When I was about 5 years old I ran into a wall and broke my arm. A few years later I wedged my head into the sharp edge of a piece of sheet metal. Around the same time I almost scalped myself on a towel hook while running naked around the kitchen (there's still a 2 inch scar right here, can ya see it?). When I was in secondary school I broke a thumb in a fight by having it bent back until it came within a knat's dick away from touching my wrist. The next day I did it again - with the other thumb.
All these things I took stoically, with not more than a whimper (OK, maybe I screamed just a little when I broke my arm. Hey, I was 5. Lay off.)
So why when 5 minutes ago I got a paper cut on my left hand did I faint embarrassingly into a bag full of empty bottles?