I've had quite a few and that is probably one of the main reasons why I think before I talk now.
When I was younger I worked at T.G.I.Fridays as a server. I go up to a table, introduce myself and ask them if I could get them something to drink. They look at me, look at each other, and then continue to read the menu. I repeat my question and receive the same reaction. So I do the fake sign language thing and do the whole talking like a deaf person thing as a joke. Well, it turns out the man at the table really was deaf and was waiting for his lady companion to translate what I was asking.
Same restaurant this lady comes up to me and asks me if another server is around. So I go in the back and find her in the smoke area and tell her that someone is out front to see her. She asked who it was and I said, "I don't know. Some fucking ugly fat bitch that probably wants to complain about our small food portions!". Turns out it was her mom.
Here's another one and the sad part is that these are all 100% absolutely true and not pulled from some mass email or website. When I was 17 I was a host at our local Red Lobster. When couples would come in with their kids I would jokingly say, "2 and a half?" - and it was alway met with laughs and smiles. So one Friday night we're totally slammed and I see out of the corner of my eye a lady, a man, and a kid. So I grab 2 adult menus and the kid's menu and say, "2 and a half?" That's when I hear the "midget voice", you know the voice and it barked out, "Um, pardon me but I consider myself a full person!". I looked back and it was a midget.
How about you? Ever have one of those moments when you just want to crawl under a dark rock and die?