To get the ball rolling: Went to a party at a mates flat and looked for somewhere safe to leave my helmet, a place where it would be unlikely to be knocked over, tried on, kicked over etc. Best place seemed to be the bath, so in it went. Some hours later I decided to leave, and stumbled over party detritus and comatose bodies to the bathroom. My helmet was still there, unscratched. But somebody hadn't quite made it to the toilet bowl and had thrown up in it. That was 25 years ago, but I still recall the feeling of freedom on the way home as the cool night air swirled around my helmetless head.