self inflicted head wounds continued

When I was 15ish i did it again. We were in the converted basement of my Buddy R, the basement had an average height ceiling with large wood beams every 6-8 feet. For some reason R and E were walking side by side, and since I'm a hyperactive freak I ran up behind them leapt at them putting a hand on each of their shoulders and tried to vault between them. My head hit the beam squarely with a loud thwock and I crumbled to the floor in a puddle. I was not knocked out but my head was ringing so much I couldn't hear them laughing at me for quite some time.
Before then When I was in fourth grade I fell out of a jungle gym flat on my back the back of my head bounced off the ground hard enough I bit through part of my tongue.