Once, the mathematician Donald Newman(1930-2007) was struggling hard with a problem, but couldn’t resolve it by any means. He went to sleep at night and had a dream. This was not the kind of dream which gives the solution to a problem, but a dream in which he met fellow mathematician John Nash. Newman asked Nash about the problem, and Nash told him the answer. When Newman finally wrote the paper, he gave credit to Nash. (I’m not kidding, read the story in this book or in the Scientific American ).