I was reminded today (through unattributed quotation) of a joke that goes like this:
Q: Who told the bear he couldn’t go to the school dance?
A: I don’t know, just, whoever’s in charge of that decision?
I can’t remember where I first heard this. I am pretty certain it was on the TV rather than something I read in a book. Do you know where it came from?
I don’t know but it sounds like the kind of line Chandler from Friends would deliver. There are other characters like that on TV and in the movies so I’m not saying it’s him specifically.
These are basically un-jokes or anti-jokes. They are set up as a joke and you expect some sort of clever answer but instead you just get a realistic answer.
Unfortunately TVTropes doesn’t give any good examples other than standup comedians like Groucho Marx and Andy Kaufman trolling a difficult audience.
Q: What’s this? (hold up your right hand, flat, palm perpendicular to the floor. Curl and straighten your fingers as you slowly move your hand from right to left)
They’ll say, “I don’t know.”
A: A flock of these. (Do the same thing, using only one finger.)