After consciously working on a problem, we need an incubation period, when we refrain from conscious thought and let our unconscious roam. This incubation period, says the psychologist Jonathan Schooler, is for ‘letting the mind wander’.3 New ideas often come to us not when we are hard at work on a project but when we are going for a walk, taking a shower, thinking about something else. These are the Aha! moments, the epiphanies, of creativity, and we are now beginning to get some insight into the biology underlying them.
