No not your worst scar, not the story that makes you sound like a badass. I want the one that the scar is so stupid or from a stupid event that you can't brag about it.
I shall open with mine.
Back when some Band-Aids came in metal tins I managed to cut my left hand up on a Band-Aid tin. I still have a scar on it that looks like the letter y. The lack of sharp edges did not prevent my past self from finding a way to cut myself.