For creativity you need your mind to wander,” Dr. Schooler says, “but you also need to be able to notice that you’re mind wandering and catch the idea when you have it. If Archimedes had come up with a solution in the bathtub but didn’t notice he’d had the idea, what good would it have done him?

Mind wandering while trying to achieve a task activates various parts of the brain allowing you to, in essence, have multi-core processing.