Earlier this week I was called out to the reference desk because there was a patron requesting a very specific book and he was getting frustrated that the library assistant on desk couldn't find it. I eventually helped him ID it once I understood that it was a niche geneology title. Let's say for the sake of argument it was "The Schmidts of Oklahoma." We did not own it, of course, so I worked with him to place an interlibrary loan request for it.
Me: "And do you have your library card with you, sir?"
Patron: "No, I'm afraid I don't."
Me: "No problem. We can look it up by your name."
Patron: "Paul Schmidt."
Me: "Well, I guess I should have guessed that, huh? Although I suppose the book could be about your mother's family."
Patron: "She recently told me they were all known criminals back in England. [pause] Not the Schmidts, though, the Schmidts have a pure record [laugh]."