It's almost become a cliché: “I get my best ideas in the shower”, but like all clichés it's based in truth.
It's not just showers; it's any simple mundane activity that doesn't require much thought: walking, cycling, mowing the lawn. Agatha Christie said, “The best time for planning a book is while you're doing the dishes.”
I will go into more detail on why these activities are so good for coming up with ideas later, but first I have to reiterate what I've said in the last two chapters: good ideas don't appear out of nowhere; you need to have thought long and hard about a question beforehand. You have to be passionate about finding a solution and a little obsessed.
If you've done this, then that's when these simple physical activities can help you. The door between the conscious and unconscious only opens one way. You can't go into your unconscious, but ideas can come out. What these activities do is oil the hinges of the door to your unconscious, to help it open more easily.
Professor Jonathan Schooler of the University of California created an experiment to test out this theory. He took three groups of people and gave them each a minute to think of as many unusual uses for a house brick as they could.
They were ...