Sleep is one of the most important aspects of our life, health and longevity and yet it is increasingly neglected in twenty-first-century society, with devastating consequences: every major disease in the developed world - Alzheimer's, cancer, obesity, diabetes - has very strong causal links to deficient sleep.

Until very recently, science had no answer to the question of why we sleep, or what good it served, or why its absence is so damaging to our health. Compared to the other basic drives in life - eating, drinking, and reproducing - the purpose of sleep remained elusive. Professor Matthew Walker discusses with Matt Brittin twenty years of cutting-edge research to solve the mystery of why sleep matters, how caffeine and alcohol affect sleep and why our sleep patterns change across a lifetime -- this is a talk that will change how you think about bedtime!

Visit YouTube.com/TalksatGoogle to watch the video.