What's the stupidest injury you've incurred?

Not serious, but unusual and hurt like a sumbitch:

It was after a kid’s outdoor birthday party, we were cleaning up. We had stuck balloons into the wood deck with thumbtacks.

I was pulling the balloons off when one stubborn thumbtack was not releasing from the deck. I pulled harder. When it finally did release, it sling-shotted right into the middle of my thumbnail, pierced the nail, and stuck there. I had to extract it.

Ouch.
mmm

Stupidest was probably the time I touched a hot oven rack with my bare skin. The thing is, I knew the rack was hot, and that’s why I touched it with only one finger. Why my logic didn’t extend further to “don’t touch it with any finger at all”, I don’t know.