Customer: My keyboard is not working anymore.
Tech support: Are you sure it’s plugged into the computer?
Customer: No. I can’t get behind the computer.
Tech support: Pick up your keyboard and walk 10 paces back.
Customer: OK
Tech support: Did the keyboard come with you?
Customer: Yes
Tech support: That means the keyboard is not plugged in. Is there another keyboard?
Customer: Yes, there’s another one here. Ah…that one does work…