The reason why you get a disease is because your sleep is [music] not restorative. I've got this beautiful 18-year-old who's about to go to college. She comes to see me for daily headache. She has a sleep study that shows none of these phases of deep sleep. She usually sleeps for 10 hours. [music] So when I ask her when we first meet, how's your sleep? She says fine. She has no deep sleep at all. And every 15 minutes or so, her brain is trying to get into these one of these deep sleep phases and she wakes u ...