This is something that has been puzzling me for years. Women will stand there watching their items being rung up, and then when the till lady says, 'That's PS4.20, love,' or whatever, they suddenly look as if they've never done this sort of thing before. They go 'Oh!' and start rooting in a flustered fashion in their handbag for their purse or chequebook, as if no-one had told them that this might happen.