I hear two questions on a fairly regular basis. The first one is 'what's the book about?' I don't like that one. They expect a black-and-white answer. That said, I can usually BS my way through. (They need to have a BS-ing class in schools, because that's a very important life skill.)
The other one is worse. 'How do you write?' Or something very similar. I SHOULD go the mature route and say 'Why, I outline, do character bios, plan for six months, etc.' What actually comes out is the following:
Really, that could be me. Only with thumbs and...you know, human features. And no fur. I think it disappoints people. Maybe I should start to lie and give them the 'mature' answer above.