Man, this is an instance there are so many examples I can't think of one
Surely one of the dumbest things was when I was 10-11 yrs, which involved a bow & arrow, marshmellow, lighter fluid & match. Beautiful secluded Marlette Lake area. I set off 1-2 before I realized this could go very badly
For a more current dumb, I recently spoke to a crazy lady in a cemetery