I have the best one ever, thankfully, not one of mine!
I was working at the election polling station, when the lady next to me got a panicky phone call from her 18 year old son, from college I might add, so supposedly intelligent.
"No darling, it doesn't work like that, your jeans will be fine, but your shirt will be wrecked."
Transpires he had accidentally put his new white shirt in with his posey designer jeans, this was when dark indigo jeans were cool, he was worried the shirt would bleach (or in fairness to him, take the colour from) his precious jeans, and wanted to know how to do an emergency stop on the machine and get the door open.
My own teen drives me to distraction, but actually always has done. I think it's the expectation of improvement with age that disappoints. He is simply a bit more adept at one line retorts, a lot taller and far smellier by the evening.