It seems that it’s rare for someone creative to maintain a constant high level of freshness. Many people, in the course of acquiring great understanding and knowledge of a subject, become conventional in their thinking. Others, like Richard Feynman, the theoretical physicist, manage never to lose their ability to come up with fresh ideas. In other words, they learn to nurture their unconscious, and to trust it. Feynman spent a lot of time playing the drums. The great mathematician John Conway spent much of his time playing games. Playing… keeps you ‘fresh’.

