Play with black powder. I must have been in early high school and begged my dad to buy a tin (had to be an adult to buy). We weren't really gun people. Dad had a few pistols that we shot at a range infrequently so black powder was something we never had in the house. Anyway, my dad caves and buys it for me for unknown reasons. Flash forward a couple weeks and my younger brother and I thought we could make "ninja bombs" which were black powder tied in little bits of paper towel. You'd light it and it would ignite quickly and make a decent amount of smoke which we thought could conceal a ninja getaway . We soon tired of the smoke bombs and my dumb ass decided it would be a good idea fill up the hollow metal tube that was the top pieces of a bench swing frame. Filled up as much as I could push in and stuffed a paper towel in. Lit the paper towel on fire. KABOOM! An enormous bang and and an insane amount of white smoke was everywhere. I was still alive. My brother was still alive. We had created a cannon and thank God not a massive pipe bomb. Anyone standing within three blocks would have heard it and seen the huge smoke cloud that rose to the sky. My brother and I immediately ran inside and flushed the black powder and vowed never to tell our parents what happened. Somehow, our neighbors didn't call the police. I ended up breaking my god a few years ago and told my mom about it. She gave me a very appropriate wtf look and we haven't spoken about it again.