Back when I was 6 or 7 I was in Austria, all excited at the thought of skiing for the first time. There I was going down a gentle blue slope which I thought was pretty impressive at the time, feeling pretty pleased with myself.. and then I crashed into a bunch of snowboarders, landed awkwardly and broke my leg. The worst part was there was no way of getting to a hospital so I had to be effectively carried down a slope, shoved onto a chairlift, get pulled of the chairlift, get put on the back of a snowmobile and get taken to hospital. Kind of ruined my first skiing trip
My other worst injury was probably 3 years ago, we were on a history trip to see WWI battlefields and trenches, and there was this one trench that went into a pitch black tunnel for part of it. Stupidly, me and a couple of others decided to run through it (why we did it I still dont know) and so I was sprinting through one second and then the next I was flat out on my back. Turns out there was a rock ledge hanging down which I smashed my head on and it must have knocked me out for a couple of seconds because I dont really remember hitting it or falling over. Anyway, I was initally surprised that it hadnt hurt that much so I stood up and calmly walked out of the tunnel and that was when I felt all the blood streaming down my face. Turned out I'd cut my head pretty badly and I had to go to hospital to get loads of stitches into it. Ended up missing one of the battlefields because of it, the Belgian hospital was very nice though