The stupidest thing I've ever done is try to blow out a gas fire as a kid. There were three of us gathered around a soup can filled with gas as a demonstration of a campfire candle. We all, on the count of three, tried blowing it out. The result was a fireball engulfing our heads. I got the worst of it singeing off all of my facial hair and the hair on my head back to my ears. Important safety note: gas fires cannot be extinguished by blowing them out.