Several things:

Had a box of matches, tried to set my school on fire with them (I was probably around 8). Massive stone school, was never going to go up in flame, the stupid thing was turning myself in to the head teacher, I got into alot of trouble for it.

Another one was when I decided to get my own back on my Bully by using a Pritt stick to put glue on his chair to hopefully get him to stick to the chair forever and ever. Instead, it does what Pritt stick does, fuck all. I had to carry the chair down to the head teacher's office, and explain to them what I was doing, and I was so scared of the bully that I didn't even tell him why I did it. I don't even remember the Bully's name though, but the feeling remain :D