My skull seems to be some sort of blunt object magnet.
As a small child, perhaps 5 or 6, I was playing with a ball in my father's auto repair shop. There was no work going on at the time, no machinery running, et cetera et cetera, but my ball rolled under an engine that was suspended 4 feet in to the air. I went to retrieve the ball, bent over, picked it up, and must have misjudged how high the engine block was above my head, as I stood up with quite some force, smashing the back of my head against the engine. I was taken to the hospital, and given several staple to close up the wound.
A few years later, at perhaps 10 or 11, I was riding my bicycle around the block. Taking my eyes off of the area in front of me for a moment, I failed to realise that there was a small children's wagon directly in front of me before I was within some 4 feet of it. Not wanting to fly over the handlebars after the rapid deceleration of my front wheel, as Tupac experienced, I attempted to bail off of the bike to my left hand side. Since I was traveling at a decent speed, I stuck my arms out to break my fall against the asphalt, but still managed to make contact between the road and my face just above my left eyebrow. I must have skid on my face for a good 4 inches. This, however, was not the worst part. Somehow, my bike had continued to move towards me at a slow rate (I assume by flinging myself from the bike, I removed most of its kinetic energy). By now my body had come to rest a good foot away from the bail-site, and the bike creeped up next to me, and fell on me, sending the left handlebar through my unprotected skull. I walked home in a daze, thinking that I had escaped unharmed. Somewhere along the way home, I figured out I was bleeding profusely, and began to panic. I rushed home, probably accelerating the bleeding. I was again taken to the ER for staples, though this time many more were necessary. The doctor said that I was lucky I was able to get back up to get help immediately, and not knocked unconscious on the pavement, bleeding from the head.
To this day I have a deathly fear of anything that travels at anything faster than a brisk jog, and will not ride a bicycle at high speed, nor without a helmet.
