When Bob asked me a couple of days ago to give this talk, he said it should be “pithy and wise.” When I spoke to Aris the next day he said it should be “informal and funny.” Then Elizabeth spoke to me and said it would be great if it was “controversial and challenging.” I mentioned to Aris just before dinner that I had put a talk together, and he said “Oh, you've written a talk—I thought it would be something more spontaneous!” Faced with an obviously impossible spec, I did what any reasonable programmer would do and rewrote the spec myself. So what I'm going to talk about this evening is a reflection on my week in Oxford.