Dialogue at Von's

Me: I'd like to buy some stamps.

Her: How many do you want?

Me: 20.

Her: Well, we sell them in books. Do you want 20 books?

Me: No, I just want 20 stamps. I think a book has 20 stamps in it.

Her: Well, let me see.

[Five minutes of her trying to get the stamps out of the cash register. Customers behind me getting impatient.]

Her: (counting out loud)

Her: Actually there's 21 stamps in a book. 20 regular stamps and one big one.

Me: (incredulous) Uh, that will be fine.

For reference, a picture of the book of stamps.