Yesterday my watch was 10 minutes late. My friend tried to coax me to enter the cinema but I thought we still had time, and he referred to his watch and mobile phone, as well as another passing acquaintance's watch, to convince us he had the right time. I've been the punctual one for so long that it seemed implausible that my timing was wrong. But it was. Never believe so much in your own judgement that you refuse to listen.