In “Why We Sleep,” Dr. Matt Walker explains how sleep can make us healthier, safer, smarter, and more productive. He provides knowledge and strategies to overcome the life-threatening risks associated with our sleep-deprived society.

Walker is on a mission to change our attitude about sleep with a book that aims to demystify what sleep is, warn us of the consequences of sleep deprivation, explain the world of dreams, and give us practical advice on rest.

The National Sleep Foundation recommends an average of eight hours of sleep per night for adults, but sleep scientist Walker says that too ma...