Witnessed - hugely pregnant woman comes in, says Name is Brown, I have a reservation. Host looks terrified: The party they had just seated said They were the Browns! Pregnant woman turns to companion and says, that's the last time we use YOUR name! I had to ask. Hers was Slavic, long, and vowel-less.

My own tend to involve closet cilantro: I recall once ordering something and asking to have it without cilantro, got my food, took a bite, and had to spit that mouthful into my napkin. Called waitress over, she said I told them no cilantro! Goes to kitchen, reports back that the cilantro is an integral part of the dish, not a garnish, so the kitchen just ignored her as it would have meant tuna, lettuce, and absolutely none of the seventeen other ingredients in my dish, because they were all already mixed. I say OK, no biggie, but I don't want any food now, too grossed out to eat anything. (There were a bunch of us. I stayed for the camaraderie.) I mean, really.