I had one encounter with Stephen Hawking. He came in the summer of 1989 to the Aspen Center for Physics and had the office next to mine. He travelled with an entourage with whom he could communicate with his voice synthesiser. His hands still worked well enough. He gave a full house public lecture and afterwards Sidney Coleman presided over a question session. Hawking had to type out all his answers on his voice synthesiser which took a lot of time. At one point Sidney said: 'You can have it fast or you can have it good.' If I had asked a question, it would have been: how did he come up with the idea of Hawking radiation? I have always found his paper hard going and have always marvelled at the simple result at the end. In A Brief History of Time he gives an account which explains the phenomenon but not the result.