I'm with you though. I thought I was doing a good job on sleep and then picked up a Charge 2 and was super surprised at just how little I was getting. It's helped me get better at going to bed at a reasonable hour.
I don't sleep much, I never have. However, I can pretty much shut my body down and meditate, which probably has similar outward physiological expressions as sleep.
I call it my time in my rejuvenation center. It isn't sleep. I'll do that for hours and then get three to five hours of sleep - estimating, of course.
When I did my sleep study, they asked me to not do that. So, I sat there awake and it was not a very fruitful study. I am sure I am not unique but I am only finding generic information when I search.
I stay nearly perfectly still, inasmuch as a human can, and meditate. Once I am asleep, I guess I toss and turn, as well as snore. I highly doubt that I am unique, in these regards.
The proscribed medical solution is a rotation of pharmacutical sleep aids. I don't usually bother with them, as I dislike the groggy feeling that I have the following day.
But yeah, I am very much awake. My pulse rate slows, as does my respiration. At some point, I'll change position and that's when I have actually fallen asleep. The duration varies, and I sometimes just give up and go do something else.