Sleep Paralysis...

[GUBU]

https://en.wikipedia.org/wiki/Sleep_paralysis

https://www.youtube.com/watch?v=gY2gh51KdnQ

Sleep Paralysis (AKA Old Hag Syndrome) is a not uncommon stress and fatigue induced sleep disorder that can produce very realistic visual, auditory and tactile hallucinations.  Many features of an SP episode are common across all cultures and belief systems and can explain why belief in the supernatural persists. 

Anyone experiencing an SP hallucination might think that they have been visited or attacked by an 'evil' spirit, ghost or demon.  Like one commenter in the linked video says, it can be more frightening and terrifying than anything experienced in real life.  Although rare, I have experienced  several episodes myself in my life and can attest to the fact that they can be most unsettling.  I have twice 'seen' the Old Hag.  Other times there has been an overwhelming sense of an unseen 'evil' or malevolent presence in the room with a feeling of being cloaked in a  black shroud. It's like having a very bad dream, but while you're partially awake. 

Although I never once believed that there was anything supernatural going on, I didn't learn what the actual cause or reason was for these episodes until very many years after having experienced them.  Has anyone else here had a similar SP experience?  Once you've had an episode or two yourself, you can appreciate why some people will believe in the supernatural.  I just wanted to reassure anyone who has experienced this and does not understand what is happening, that although quite terrifying, it is otherwise benign and harmless...

I used have awful nightmares as a child, that the parents couldn't wake me up from. The only one I can remember now was a night when we were caravanning down in Cork, and I started dreaming that the walls were getting bigger and farther away. Even after I woke up I was still seeing them receding. I lay there on the floor not able to move (so I believed) screaming about the walls getting huge.

I'm not 100% sure that was sleep paralysis, but I'd be confident it was something similar.