Share your experiences that you've had with "experts" who have made you want to facepalm from their stupidity and users which have less than minimal knowledge. For example, people that wonder why their computer doesn't turn on during a power cut.
My most recent one that I can recall is when I was doing a temp job a few years ago. One of the people there had moved desk and the network cable no longer reached his computer so what he decided to do was place the tower at a point close enough so the network cable would reach and then after logging in, he unplugged it and moved the tower back to his desk. He then kept complaining that the internet wasn't working and he couldn't access any network folders. I tried explaining to him that the network cables needs to stay plugged in to access the network but he was adamant that it only needed to be plugged in to log in. He seemed to be the type of guy that thinks "I'm older so I must know more."