(The customer arrives very angry at my desk. He nervously holds a memory card in his hand.)

Customer: “I want a new memory card. This one is really bad!”

Me: “What troubles do you have with this one?”

Customer: “It only makes blurry pictures!”

Me: “Well, I guess the problem might be the camera, not the memory card.”

Customer: “Oh, and do you have memory cards in black & white?”

Me: “Or it could be the photographer…”