Bookstore Order

A man walks up to a woman and says, "Ma'am, I'd like to order a Guinness."

The woman looks at him and says, "You must be Irish." Offended, the man replies, "Oh, so just because I'm ordering a Guinness, you assume I'm Irish? If I ordered a pizza, would you assume I'm Italian?" "I didn't..." "And if I ordered a Bratwurst, would that make me German?" "No, but..." "So why the hell do you think I'm Irish then?" "Because, sir, this is a bookstore."