Have You Played... Spank The Monkey?
Perhaps while at school
Have You Played? is an endless stream of game retrospectives. One a day, every day, perhaps for all time.
When the teacher wasn't looking in computer class, me and all my friends were doing this. You can still do it now. Grip your mouse with one hand and play Spank the Monkey.
Monkey was one of a spate of Flash browser games that seemed to all be about measuring the speed or distance at which you could do something. You'd move the mouse one way and back again to launch an animal into the air or, in this case, smack an inflatable monkey with a large swaying hand. The hand swaying is still very satisfying.
But there's a sub-game in there, too. Swinging your mouse the 'official' way has a hard limit on the speed it's possible to achieve, but if you move your mouse so far away from the monkey that your pointer exits the playable area of the game, you'd thus stop controlling the hand. You can then move your mouse pointer around the playable area and re-enter it from the other side, causing the hand to snap to your mouse's new position in an instant and with a force much greater than naturally possible.
You can call it cheating, but I call it a game with a deceptively high skill ceiling. We got probably another week of enjoyment as a result of trying to manipulate that bug to the greatest effect.
