To summarize, Americans and their brains are preoccupied with work much of the time. Throughout history people have intuited that such puritanical devotion to perpetual busyness does not in fact translate to greater productivity and is not particularly healthy. What if the brain requires substantial downtime to remain industrious and generate its most innovative ideas? “Idleness is not just a vacation, an indulgence or a vice; it is as indispensable to the brain as vitamin D is to the body, and deprived of it we suffer a mental affliction as disfiguring as rickets,” essayist Tim Kreider wrote in The New York Times. “The space and quiet that idleness provides is a necessary condition for standing back from life and seeing it whole, for making unexpected connections and waiting for the wild summer lightning strikes of inspiration—it is, paradoxically, necessary to getting any work done.”