I know how important it is to be polite. Particularly in a great world city like London, I know that we should all treat our fellow citizens with curtesy and respect. However, if I’m sitting at a bunch of other people at a pedestrian crossing and the lady beside me feels she needs to tell me that the light has changed to green with the most patronising, nauseating “Look, it’s green now. We can cross.” Then I reserve the right to reply with the words “Yes, I can see that you stupid bitch.” Not very polite I admit, but absolutely essential in the circumstances.