There was a game we were losing by ONE POINT. I had the ball dribbling it to the goal. I was playing soccer. I kicked it as hard as I could. Then, it went over the goal. We could've tied, but I messed the whole thing up. Probably not the worst thing ever, but it was pretty embarassing!
Mine was when I was skating on my ninth birthday. While I was skating I flipped over and slashed my head on the corner of a table. I was literally gushing blood. I had to change shirts 2 times. I almost had to get staples. If anyone even TOUCHED it the cut would start bleeding.