I had a user once who was a woman in her mid 50s. Most of her job duties were performed on the computer, so she could get around a little bit (a lot perhaps, considering that she got fired for spending upwards of 10-20 hours per week playing solitaire and shopping online).
Anyhow, she calls me up one day and says that something is wrong with her computer: "It says CHECK SIGNAL CABLE in big red letters!"
So I wander on down and sure enough, the monitor reads CHECK SIGNAL CABLE. Recognizing that the message was from the monitor itself, I started poking around at the back of the machine trying to see if anything was disconnected. After about five minutes and a big self-slap on the forehead I asked, "ummm...is your computer on?"
"Well of course it's on, it says CHECK SIGNAL CABLE."
"Yeah, but I mean the computer itself. You know, the "tower", or the "CPU", or the "hard drive", or whatever you happen to call it." (I wasn't really so snippy)
She suddenly realized what I was talking about, and she proceeded to turn her computer on. We had a good laugh about it and I went back to my hole.
About a week later I get another call: "Something is wrong with my computer. It says CHECK SIGNAL CABLE."
I was speechless at first, and almost thought she was joking. After a moment I calmly asked her if she had turned her actual "computer" on, and not just the monitor. She gave an embarrassed laugh and made some apologies and I told her not to worry about it, everybody "has those days."
Maybe a week or two later I get another call from the same lady: "Something is wrong with my computer, it says CHECK.... oh wait, nevermind."
I hung up the phone and took a moment to reflect on how fragile reality can be.
A week or two later I happen to be walking past this lady's desk and one of the guys from our engineering department is looking at the back of her computer and pulling on wires and whatnot. Being a bit dumbfounded I just decided to keep walking on by.
A few hours later I caught up with the guy from engineering and asked him what was up. Sure enough, the lady had forgotten once again to turn her computer on. What really gets me though is that she called this other guy from a completely different department because she *knew* that calling me would somehow lead to embarrassment. And while she could remember this potential for embarrassment, she could not remember that the solution to this particular problem was to simply turn her computer on.
Anyhow, that's my favorite story. Maybe you had to be there. A close second was when a much younger and more savvy woman called me to fix her mouse which was "too slow". Before I was able to get into the mouse properties in Windows and adjust the speed, she insisted on explaining her hypothesis that this particular mouse was slow because it's cord was very long.
Which brings up an interesting reality. I bet that a large number of the support calls I get are solved by having people re-adjust the location of their wireless mouse receiver, which is rarely described as "my mouse isn't working right" but more often "my computer (or 'the internet') is slow, I have to click on things ten times before they open."
Another large number of calls are solved by having people shake the crap out of their keyboards... a stuck ALT or CTRL key can be hard to diagnose the first time. :)