It sounds like a Stephen King movie, but it's actually a medical condition called sleep paralysis, and about half of the population has experienced this strange phenomenon at least once in their life.
Zní to jako z filmu podle Stephena Kinga, ale je to skutečný zdravotní problém zvaný spánková obrna. Tento zvláštní jev prožije alespoň jednou za život asi polovina populace.