Aged about 8, I had a squabble with the school bully in the local swimming pool. I can't even remember what about. But I know I've always HATED bullies, so I probably caused the squabble. She was a year or two older than me, but growing up with older sisters, I wasn't phased.
Anyway, she was wearing a distinctive-looking pair of goggles... I got out before her and went into a cubicle to change. It was quite a small changing room, and I soon heard her voice, and that of her mums, in the showers.
I popped out of my cubicle, to retrieve my shoes from my locker, and there, hanging on the dial of one of the showers, was her goggles... But she was nowhere in sight. So I picked them up, and lobbed them over to the other side of the fairly-deep foot bath you had to wade through to get to the pool. Then fetched my shoes and returned to my cubicle.
I was just about done when I heard girl and her mum looking for said goggles. Mum is ranting and raving about how they were expensive, and "you'd better find them!!" And then she spots them the other side of the foot bath...
Then a series of ringing slaps sound out. "WHAT HAVE I TOLD YOU ABOUT BEING CARELESS?! TAKE YOUR SHOES OFF AND GO AND GET THEM!" Each word punctuated with a firm smack.
Looking back, it was a pretty nasty thing for me to do, but frankly, the little bitch deserved it.