What do you need?

A man came up to me at the desk the other day and asked where the business books were located. Naturally, I needed some clarification. Sometimes, a patron says business and they actually mean real estate, or how to start a small business, or business leadership, and these would all be found in different places. So I began the usual reference interview: "What kind of business books do you need?" I asked. Offended, he responded with, "Well, I don't need any of them. I just want to look at them." "Okay," I said, quickly making a mental note that this guy has an ego problem, that this reference interaction might get worse before it gets better, and that I'd better tread lightly. Then before I could filter myself, I started laughing as I said, "Fine. What kind of business books do you want?"
Yes, I was mocking him.
No, he didn't seem to notice.