Alcohol and Caffeine, Naps, and the Science of Sleep, with Dr. Matt Walker

It's Wellness Week at the Megyn Kelly Show. Megyn Kelly is joined by Dr. Matt Walker, sleep expert and author of "Why We Sleep," to talk about the science of why we get tired at night and feel rested, the effect of melatonin and sleep aids, how caffeine and alcohol affect our sleep, the science of dreams and nightmares, how sleep helps with our memory, how better sleep leads to better sex (and vice versa), and more.