Stranger on a train

The first time I really realised how bald I was happened while visiting the bathroom on a train from London to Newcastle (don't worry, no parental guidance necessary). I'd just closed and locked the door when I happened to notice a very bald man about two feet away in the same cubicle! That was the first shock. The second, even less welcome, came when I realised that due to the positioning of the mirrors in the bathroom what I was really looking at was the back of my own head! For some reason although I'd accepted my baldness from a frontal perspective I'd never realised how bald (or how old) I looked from the rear...