Goofing off with my best friends at an indoor swimming pool when we were kids. We were running. It was all going swimmingly, until my feet went flying out from under me and I slammed down head first onto the concrete floor. I was so mortified that I immediately jumped back up, but my head felt like it had been split open. The grups all came rushing over, of course, and even strangers were getting involved, everybody asking me if I was ok, and trying to see if I had a concussion. I kept swearing I was fine, so they eventually let me go, but for the rest of the day all the adults kept a super close eye on me. I hated the attention and just wanted to be left alone, so it took me quite a few years to mention the crack in my skull....