The answer is part of today's special centered on the science of sleep. We report on the roles of adenosine, cortisol and melatonin in our circadian rhythms. We explore the benefits of quality sleep and the consequences of not getting it. And we offer tips for better "sleep hygiene" before examining the topic of sleep inertia. Plus: a look at the differences between brown, white and pink noise machines. It's an eye-opening show!