You should go into more detail on why you thought this was your worst mistake and what happened.
Mine was when I was on the bus in 9th grade. I thought I was the shit because I was one of the first few kids who was smoking bud at the time. I lit up a bowl on the bus thinking I was the man, and the whole bus reeked and I got called into the principles office. I played so dumb since I was an innocent little 9th grader, I told them I was just joking about smoking and made the kids believe me. They asked me "well what does weed look like?" and I said "like brocolli... duh!" and they fell for it and looked at me like I was stupid. It was exactly what I wanted them to think. Got away with it fortunately. Imagine how bad it could've gone though. I really do regret that. I have a lot of funny high school bus stories. I was beat off on the bus too, and also got away with it <3