We had a history teacher who wrote copious notes on the blackboard. It became a test of courage to wait until he was in the middle of writing and stand up and whip out your knob. Whoever dared to leave it out the longest, risking him turning around and catching you, was the Knob-King of the week. Once, a particularly unpopular boy, trying to ingratiate himself with the in-crowd, whipped out his knob during the lesson and the boy behind him yanked his trousers and pants down and shouted 'KNOB!' Of course, the teacher turned around and caught him. He was sent home and his parents had to come in and see the headmaster.