I met a guy who didn't know that electricity comes from electrons. He started going on about how much better the world would be if we could harness them. It occurred to me later that he probably meant positrons, but the conversation didn't last that long after I laughed at him and told him what electricity was made of.
I've heard of techs having fun with people and telling them they need to mount their wires at an angle, so the electrons can flow downhill more easily.
The computer coffee cup holder story is almost certainly true, but it's so widely known now that you can't expect to get a genuine report of it any more. Same for the guy whose computer wouldn't work when the lights all went out.
Then there are those people who plug power strips into themselves, and don't understand why the other stuff they plug in doesn't work. I've met such people, so I know that one's true.
I got one on the tip of my cerebrum that someone I know did this year or last, but can't get it to come out. Maybe I'll remember later.