There's only one thing more painful than learning from an experience, and that is NOT learning from an experience.
A couple of years ago my family and I were at a friends house for a 4th of July barbecue and someone brought fireworks. The list of goods included bottle rockets, Roman Candles and sparklers (which are more my speed).
Out of the corner of my eye I happened to notice that the teen was attempting to light a Roman Candle in the street. He was struggling to get the lighter lit and was lighting the candle with the fuse pointing towards him and the crowd. See where this is going?
When the fuse finally lit he held the candle towards the sky, like he saw everyone else, however he had the lit fuse facing towards him. It was like watching a movie as I thought, is that right? I yelled for him to turn it around. At this point others noticed what was going on and yelled as well. He looked at us and dropped his hands, luckily pointing the rocket away now....