Has anyone ever done anything for bants and then realised it was really stupid?

I was listening to Jarvis C talking about jumping from a window to impress a girl and ending up in hospital.

Had a colleague who was an amateur caver at university and boasted that he could squeeze thru a foldable gap in a chair and got part way through and passed out. Chair had to be smashed to get him out.

Friend was in vegas and somersaulted over a railing on his hotel balcony to "impress the lads" then realized he was hanging by his hands 50 ft in the air.

Stuff like that. Scary because you nearly died but funny because you dint.