Why We Sleep explains how caffeine and alcohol affect your sleep. What really happens during dreaming? Why do our sleep patterns change across a lifetime? How do sleeping pills affect us and can they do long-term damage? The book goes on to describe how we can harness sleep to improve learning, mood and energy levels; slow the effects of aging while lowering the risk of Alzheimer's, obesity and diabetes; enhance the education and lifespan of our children; and boost the efficiency, success and productivity of our businesses.