I once left some (slightly) radioactive samples from my lab in a bank. In a large box with radioactive stickers on it. On September the 12th (yes, that 12th). Police weren’t amused.
I also have reversed over my own front wheel twice (two different wheels, not twice over same wheel, that would be stupid).
Aged 14 I thought “what will happen if I hold this camera flash up to my eye and set it off”. So I did. What happened is I went temporarily blind then, after about 20 minutes, only green came back. Felt like such an idiot that I didn’t tell anyone. Took a couple of days for full vision to come back.
Those are just the ones that spring to mind, there are many many more.