 They're REM sleep by an hour, an hour and a half, maybe two. REM sleep is not a very easy thing to get into. You need to be in a deep state of sleep. That is the last step of sleep, and that is the most recoverative point of your sleep. That's where your body is going to be repairing itself. That's going to be recovering from all the things you took on that day. So it's very beneficial to know.