There are also the customers you feel really shouldn't be out.
One lady came up to me, whilst I was in the basement, and said in a sweet, nervous voice "How do I get out of here?" whilst standing next to the staircase...
One guy came into the bookshop looking for a bottle of whiskey.
A Policewoman tried to correct me on retail law, and got it wrong.
Two kids today said "What sort of bookstore is this when they haven't got the book I want?", so I turned and said, loudly, "Well, we only have room for 10,000 books."
My favourite story.
"Excuse me, where are the rubber stamps?"
"I'm sorry ma'am, we don't have any."
"How old are you?"
"Excuse me?"
"How long have you worked here?"
"Well, five years at the moment."
"Then you are too young, who's the oldest person here?"
"That would be me. The Manager."
"My mother told me she got some stamps in here ten years ago. Where are they?"
"Madame, we have never stocked rubber stamps."
"You are useless. I will come back when there's someone older."
I think that was actually a compliment, especially as the others were only 18.