Fall for a Jehovah's Witness >_>
No, the stupidest thing I've ever done was when I was about 3 years old. Waddling along in the kitchen, look up at the shelf, see a cup. That's an interesting cup, I innocently think, I better see what's in it. So I reach up, and topple the cup to see what was in it.
What was in it was scolding hot coffee which immediately went all over my arm. Stupid me is not scalded, burnt me. I managed to escape with a third degree burn all over my arm, and luckily the scar has completely faded over the years, but this is still a cringe worthy story in my family.