A German tourist walks into a McDonald's in New York City and orders a beer. (In Germany and many parts of Europe, McDonald's actually does serve beer.) The local guy in the line behind him immediately gives him the jab: "They don't serve BEER here, you MORON!" The German fellow felt pretty stupid, but suddenly turns to the New Yorker with a surprised look, and begins to chuckle.
"And what's so funny?!?" the New Yorker demands.
"Oh, nothing really, I just realized that you came here for the food."