Scientists have long wondered why we power down our brains and spend countless hours in light dreamless slumber. Dr. Matt Walker and his research team at U.C. Berkeley’s Sleep and Neuroimaging Laboratory have found compelling evidence for the purpose of this kind of sleep. Their findings suggest that it can solidify newly learned memories by rewiring the architecture of the brain as well as refresh emotional brain reactivity, effectively ironing out our prior waking concerns and allowing for well-rested rational next day decisions. Sleep benefits us not only in learning and memory but also in many other ways that improve our health.