If we don't get enough sleep we don't function very well. Some people are very lucky. They're called short sleepers and they buzz through state is wanting to sleep and just get the good stuff. And they may need only four hours of sleep and function perfectly. These are presidents and CEOs, and very busy and productive people. On the other end of the spectrum, we may have long sleepers people who literally need nine or 10 hours of sleep to function. Well, everybody's different. Probably we can get away with one hour or less than we need and still be okay. The next day, when people tell me that they can sleep an extra two or three hours on a Saturday morning, it would tell me that they're sleep deprived. And this is probably the biggest and most under-recognized sleep disorder in America. Sleep deprivation.