(I am shelving books when a young lady, probably in college, comes up to me.)

Patron: “Excuse me, miss, could you please help me find a book for my class?”

Me: “Sure, no problem. What’s the title?”

Patron: “I can’t remember.”

Me: “Well, okay, what’s the author’s name?”

Patron: “I don’t know.”

Me: “Can you tell me what the book was about, then?”

Patron: “It’s for literature class!”

Me: “Yes, but can you give me any idea what it might be about? Is it fantasy, science fiction, a mystery?”

Patron: “I don’t know yet. I haven’t read it!”

Me: “Um…do you know anything about the book?”

Patron: “Yeah. I think the cover’s blue.”

Me: “…Then how are you going to find it?”

Patron: “I just told you: I need it for class! Can’t you just help me?”

Me: *giving up* “I’m sorry, ma’am. I can’t find a book with nothing but the color of the cover.”

Patron: “But you work here! Isn’t that your job?!”

Related:
Judging A Book By Its Cover