I get that a lot when I'm drifting off to sleep with a good buzz. The funny thing is I know that if I really wanted to I could move, but there is some mental block that keeps me from doing it. I usually have just enough time to think wow, this is pretty cool, and then I'm asleep.

What's even more strange is when I'm laying there almost asleep, and it feels like half of my body is asleep and the other half is awake. Pretty sweet, but it too only happens when I'm high.