Re: Childish but satisfying...
In a previous working life two members of my team had a friendly rivalry that occasionally wasn't so friendly. They loved playing practical jokes on each other.
One week colleague A (let's call him John) was on holiday, so colleague B (let's call him Peter) decided as a practical joke to remove all the keycaps from John's PC and replace them in a random order that was nearly correct but not quite. We pointed out that this was perhaps a little foolish as he would be going on leave almost as soon John returned.
On John's return he had considerable difficulty using his PC; log-on wasn't too difficult due to muscle memory, but anything else caused huge confusion. It took him a while to work out what was wrong nut no time at all to guess who was responsible and vow revenge.
Fast forward three weeks....
Patrick has just returned from two weeks' holiday. First morning back he sits down at his PC, examines the keyboard carefully, then looks up at John and observes that it was pretty pathetic joke to just copy what had been done to him.
He then spends several minutes rearranging his keycaps into the correct order and logs in. Only he doesn't. The login fails. And fails again. A microscopic examination of his keyboard follows, even borrowing mine for comparison. Convinced the keycaps are in the correct place he tries logging-in again and fails again. After five tries he rings the helpdesk to get his account unlocked and gets them to change his password as - clearly - he's forgotten it.
He tries logging-in yet again...
It took him all morning to realise that his keyboard had been remapped as a Hungarian one