So I've had this experience a few times and its always weird.

sometimes my arms will start dreaming while the rest of my body dont and when I try moving my arms, it will feel perfectly normal as if they are moving, but they are actually paralyzed in bed already while the rest of my body can move.
today I had a false poistive reality check because of that. I tried closing my nose and breathing through it and it worked, I was really confused because It didn't feel like a dream at all (and it wasnt, kinda) but my arm was dreaming that it had closed my nose so the reality check gave a false positive.

Wonder if that had happened to anybody else?