When I was about 9 or 10, I was leaning back in my school chair. Of course I managed to topple over and hit my head against the brick wall behind me. After a brief visit to a local hospital, I spent rest of the day resting at home with a big lump on my head and a minor concussion to top it off.
Another silly injury happened during my conscript service. We were on a 30 kilometer ski trip and were nearing our destination. I was getting pretty tired and managed to slip and fall on my back on a downhill slope. Normally that wouldn't have been too bad, but my assault rifle http://images4.wikia.nocookie.net/__...a/RK_62_76.jpg
, which was hanging from my neck in front of me on a leather strap, decided to come along for a ride. It made a beautiful arc in the air and hit my face next to my nose. Luckily it only caused a bleeding wound that looked worse than it really was and a tiny hole in my gum. Little lower and I probably would have lost one or more teeth. That thing weighs about 4 kg, after all.