Never got into too much trouble with electricity, I had the presence of mind to complete the circuit with something much less conductive than myself. Not bad for a kid in grade school.
AC adapter > staple > metal back of a cheap watch > staple > AC adapter. I managed to fuse both staples to the inside of the adapter. They had to be drilled out before that laptop could be charged.
Played around with fire quite a bit. Thankfully pyromania runs in the family and I've picked up some things about not setting yourself on fire in the process.
No, the real fun one was getting hit by a bus. I was riding a bicycle near a sharp bend in the road, and was turning left. There's a reason they tell you to check before you turn - the bus had just come around the corner, and was in the other lane having passed an elderly gentleman going slowly. The road is marked 55 mph, and the bus was probably doing about that to pass him. Was going ~5 mph, accelerated as the bus pushed me for a couple seconds, got shoved off to the side, and skidded along the pavement until I stopped. Faded in and out of consciousness for a minute, then got to my feet and tried telling the rather concerned crowd getting out of their cars that I could walk home. Wound up with asphalt burned into my elbows and knees. Parents said it was fine, then took me in the next day when my knees were solid yellow with pus.
Fun fact: doctors will remove burned-in asphalt by abrading it off, using a rag soaked in iodine solution to fight infection. I'm told the process took about twenty minutes for all four limbs. I have to rely on outside judgement here, as I spent the time in intense agony, squeezing first a lamp and then a hand to minimize my own reflexive motion.
Had to use more iodine every day for weeks, and my one knee is solid scar tissue. Still glad that the bus pushed me out of its path, and that I didn't wind up with anything broken. Also, I had a gameboy advance in my pocket, the cloth of both my shorts and the pocket eroded away and the handheld skidded along the pavement - it still plays fine, and there's only a small (1 cm wide by 2 long) scratch in the plastic on one corner.
Lesson: don't get in front of buses, they're bigger than you and you don't have impact-tested sheet metal to absorb the impact, nor to keep you from contact with the road.
Also lesson: jeans and leather aren't just badass, they're a good way to avoid having petroleum-based substances fused to your skin.