I've posted about this before, but here are a few more which I find bewildering:
Q: Are you going somewhere nice for your holidays?
A: No. We're going somewhere really horrible.
Q: Is there anything in the (news) paper today?
A: No. Just thirty-six blank pages, as usual.
Q : (from a shop assistant) Were you looking for anything in particular?
A: Well, I was, but not any more.
Q: (similar to the above) And what was your name?
A: Well, it was Winterbottom when I came in, but I've just changed it to Middleton (why not?).
Q: (following on from a rant from my daughter yesterday, who had just been asked this in Waitrose):
Do you want a carrier bag at all?
A: Well, a bit of carrier bag would be fine. Just one handle, I think.