I know I've told this one before, but:

I get a "I can't get the system to turn on.", and when I arrive the guy isn't there, but his gal friend is, and she is watching TV on the system.

He walks in and says "Ah, you got it working, what did you do?".

I told him to ask her, and she says "I pushed this button that has ON printed on it.".


Didn't bill him since the laugh riot afterwards made my day.