So we go through in the beginning of the night, we go into the really deep stages of sleep and we actually cycle through. So, when you go down to the deep stage, then you go back up and you actually come into something called REM sleep, which is after about 90 minutes.

For some people they say, it's about wish fulfillment, it's about the things you are never able to do in your day you are actually fulfilling at night. There are other people who will say that it's actually telling you something.

If you're going somewhere East from here, generally what you want to do is you want to try to have your bed time earlier and earlier so what we'll do is I'll have someone adjust for a week or two by going to be 15 minutes earlier and getting up 15 minutes earlier every night. So that can be a really simple thing.

So you have Sleep Stage One, Two, and then Three/Four. One is a little bit lighter stage of the quiet, non-REM sleep and then Three/Four is really deep, deep sleep. And what you want is, you actually want a number of - you want to go through all of these stages throughout the night.

In general, there are patients with insomnia who - many patients with insomnia will actually over report the lack of sleep that they are getting.

Now circadian rhythms become very interesting and problematic for patients because when you become a teenager, your rhythms actually tend to naturally shift.

So people only focus on getting the really deep sleep, but in reality, we spend almost 60% of the night in the stage two sleep.