if it's what i think it means, (kinda being stuck between half asleep and half awake and not knowing wtf is going on or that you're asleep) then it happened to me maybe 4-5 times. i noticed it happens to me when i sleep with my arms restrained. Say i fell asleep in a weird position body over my arms or maybe i fell asleep wearing a hoodie with my hands in my pockets, i notice that because i can't move like i want to wake up, i just stay in a sort of haze. the few times it happened i was wondering if i was dying/dead and trying to remember how i died.