[quote=Cordi]
I've slipped into it before after a lot of practice. It's a pretty interesting experience. You can move around to break it but It's trippy, there's about a very long 15 second delay from you saying "dammit arm, move" before it actually does anything. Every time I think I'm about to fall asleep when attempting it, it creeps me out because my eyes just open and I can't close them. I haven't seen anyone at the foot of my bed but usually out of my peripheral I see shit that freaks me out.
[/quote]

Interestingly, Acetylcholine has an extremely short Half-life (~2 minutes). This could explain why it takes your body only a few seconds to a minute to "Shake out of it." 
I've also heard of people just closing their eyes and trying to fall back asleep, but I could never do that since it feels like if I go back to sleep, I'll be paralyzed forever.