I did so many stupid things as a kid, most of which resulted in me getting into trouble, breaking bones or getting into fights.
I broke so many bones one year, the hospital thought I was being abused at home and asked me if my parents hit me! Some of the highlights:
I dropped a gravestone on my leg and broke my leg in several places
I built a ramp at the bottom of a really big hill, jumped my bike really high then came off mid air and landed on my shoulder, busting my shoulder.
Built a zip slide between to really high trees using some old rope and a bit of tube to slide over the rope. Rope snapped with me in the air, landed on ---my bottom--- and knocked myself out.
Climbed out of a 3rd floor dormitory window at boarding school at night with a rope, not realising that climbing down a rope is a lot easier than climbing up it, thus getting caught
Hotwired a JCB at boarding school and took it for a spin, but couldn't work out how to turn the damn thing off, so parked it in the headmasters front garden and left it running
Thought it would be funny to fill an empty coke can with pee and give it to the headmasters son to drink. (neither he nor the headmaster saw the funny side after he drank a huge swallow)
I put purple clothing dye in the school swimming pool, but got some on my hands, so identifying me as the culprit wasn't too hard.
I removed the ballcock in the 1st floor toilet and flushed it, thinking the water would run like a waterfall down the stairs. It didn't, the water just collected above the downstairs ceiling until the plaster underneath gave way.
I picked a fight with a guy called Charlie who was beating on a younger kid. Turns out Charlie went to boxing club after school and broke my nose very effectively.
Hit Charlie back as hard as I could. Unfortunately not having Charlie's knowledge of how and where to hit someone, broke my knuckles on the back of his head.
I could go on for hours.... trouble is, some of the things I have done as an adult are even more stupid
