When I worked for a fairly large computer company I used to get idiots per hour, not just per job. One guy ordered a full system off me, which did have a couple of problems, but I bent backwards to get the computer to him on a Saturday morning.
Come the Saturday the guy was on the phone. His computer wasn't working. When it had left us it was working, I had used it myself to make sure. We also delivered via in house transport, so I was confident it would have arrived intact.
And so the checks began. Is the light on. Yes. Is it plugged in. Yes. Does it beep ever. No. Does the monitor work. No. Does the monitor get its power from the main machine. Yes. Is it plugged in. (Sometimes you HAVE to ask twice) Yes.
Is, er, the plug socket, er, switched on. <silence> Click, Beep. Ahhhhhh.
Good bye sir.