yeah its called sleep paralysis. It happens to eveeryone at least once in their life, some many times. Its when your mind becomes concious when you are dreaming but your body is still asleep. "Sleep paralysis is a condition in which someone, most often lying in a supine (face up) position, about to drop off to sleep, or just upon awaking from sleep realizes that s/he is unable to move, or speak, or cry out. This may last a few seconds or several moments, occasionally longer."