 It's very, very clear. We think better and we feel better when we're sleeping well. Not getting enough sleep can be part of vicious cycles in our lives that can lead to accidents, can lead to disorders like depression, can not let us develop in body and brain as optimally as we might otherwise. People in this age range, teenagers, are getting an average of seven and a half hours. That's falling more than an hour and a half short of the sleep that people are needing. Stage 2 sleep is this lighter stage of sleep. We get a lot of it in the second part of the night and it improves our ability to learn. The human circadian rhythm ticks at about 24 hours and 10 minutes. So we are all going to have an inclination to go to bed just a little bit later each night. And if we only pay attention to those bodily signals, we're going to be one hour late for school by the end of the week and we're going to be four hours late for school or work by the end of the month. The people who are waking up at 7am on weekdays and sleeping till noon on weekends are putting themselves in a jet lag situation and the sleep system can't adjust to that. And so come Monday morning it's really hard to wake up. One thing we can do that will really help is to go to bed at about the same time every day and that's the weekends as well as the weeknights. We don't want to be falling asleep with the television on, with cell phone under our pillow, with all this technology around us. We want to be falling asleep under conditions that are positive and sleep inducing. It's not just sleep we need for our health, it's also darkness. It's known in rodents, so rats from research, that if they are in bright light all the time, even if they're sleeping there's an increase in cytokines that trigger medical illnesses. So there's a lot of value just being in darkness about nine hours a night. So it's not a waste of time to be sleeping and even to have spent 24 years of your life sleeping it's not a waste of time because it's keeping us alive and learning and functioning well.