'Sunglasses, oohoo, to hide behind,' sang Tracy Ullman.
I certainly like to hide behind a pair of sunglasses while I'm running. It's much better if the world can't see my longing to take a break.
Also, it gives me a pleasant sense of being invisible. So when I see some men coming towards me shouting the inevitable: 'Can't you go any faster', I can pretend I didn't hear them.
Hm, maybe I should start wearing them around the children.