I do wonder if mechanics have to deal with...
I used to use that as an analogy to help people understand why I would get a bit short with them if they did something "dumb" with the computer - you know, complaining the printer's broken when it's actually not "online" or is out of paper, moaning that updating the spreadsheet takes hours, when they've hard-coded (say) VAT at 15% into every single calculation and need to change it to 17.5% (that dates me!), handing me a floppy disc encrusted with dried-on hot chocolate because "it doesn't work for some reason and contains the only copy of that database"(*). And these, not (always) from general office staff who were just shown how to switch the computer on and expected to get on with it; the spreadsheet one in particular was from a user who had just been on a three-day Excel training course!
Imagine, I used to say, that you have just passed your driving test and after a week or so of driving quite successfully to work your car conks out. When the AA man finally arrives, he diagnoses lack of petrol. "But I never had to put petrol in my instructor's car!"
Sounds stupid - who on earth could own a car and not know that it needs fuel to run?
There comes a time for all people who do "IT support", be it as an official job or just because "well, you know about computers, don't you?" when they realise that these stories they have always considered to be urban myths - things not plugged in, the mouse that can't go further across the desk, the computer not working in a power cut, the black-and-white logo scanned at 24bits and 600dpi and emailled to everyone in the entire group in the days of MS Mail running on (at best) Windows 3.11 with 4Meg and inter-site communications via 14k4 modems from a mail server with a '286 and 40MB HDD are not actually myths, but absolutely true.
(*)I actually recovered nearly everything from that floppy by dint of extricating the actual disc (it was a 3.5"), running it under the kitchen tap and replacing it in the body of a sacrificial disc. I did ask the person why they hadn't called me as soon as they spilled the hot chocolate, instead of a fortnight later when they desperately needed the data, and as far as I remember there was not even an attempt at a satisfactory reply.