The hypnotic effect of watching a window cleaner

Because we haven't had a window cleaner for our house for years and because I haven't been anywhere else recently, I had forgotten about the fact that it's almost impossible (for me at least) not to watch window cleaners at work. From a distance, it's mildly engaging, but when it's a window of which you are on the other side to the cleaner, it's positively mesmerising. I feel it's important to mention that it's the action of the squeegee which I find captivating and nothing to do with whoever is wielding it - I'm not quite ready for a role as desperate office worker number three in a Diet Coke ad - not least because I'm pretty sure that the man I accidentally ended up staring at for nearly 10 minutes earlier today thinks he has a new admirer.