The other night my wife and I were at the theatre, sitting behind a group of young people from a school party who were taking selfies. I noticed that, in my sensible jumper and sensible glasses, I had ended up on at least one because I was so close. I raised my thumb and the lad taking the photo turned round and gave me what people in books used to call 'an old-fashioned look', and I knew that, just for a moment or perhaps for ever, I had achieved a kind of fame.