TIL your body paralyzes itself when you sleep to keep you from acting out your dreams. However, it is possible to wake up while still paralyzed; many people who have experienced this claim they felt a malevolent presence nearby.

This happened to me once. Just one time. It was literally hours after probably the most shocking (for lack of a better word) experience of my life. I am not sure if the shock from the previous event released chemicals in my brain or something that lead to the sleep paralysis and hallucination but it still seems so, so weird to me that the 2 most 'strange' things that have ever happened to me happened within hours of each other. It's also still as vivid as the moment it happened which is also odd to me. We were sleeping in the living room of my wife's parents house as we were visiting them. This is literally in the middle of nowhere (an hour off paved roads to get to their house). Sleeping like normal then I awoke and was completely aware but fully immobilized. I had no clue what was happening and it was terrifying. I have to admit I started screaming but it was more frightening to realize no sound was coming out. I was trying to yell my wife's name and nothing. Next I saw a figure to the right front of the bed that was kind of, I don't know, watching me. Like as if it was observing, not in a menacing way. It was maybe 5 feet tall, slender and inky black but it was also fairly dark in the room. It had the proportions of I don't know, maybe a thin 14 year old or something. When I noticed it, it moved back through the entry towards the kitchen (the living room and kitchen are connected by one of those open walls instead of a door so they are sort of openly connected) like it knew I noticed it. It didn't go fully out of sight though. For a minute it kind of peered around the corner so I could just see it's head and shoulders with it's body hidden then it pulled out of site completely. I don't know what one feels like but at this point I feel like I am neering or having what must be a panic attack. Then boom, my Mother in law enters the room en route to the bathroom (my wife's folks bedroom is off the living room) and in an instant, as in a finger snap, I regained complete control of myself. Immediately felt overwhelmed with a feeling I can't explain more than 'what the fuck' and stammered some kind of apology if I was whimpering and that I had a nightmare. It wasn't a nightmare. I can't believe this happens to some people frequently and they have to go through this repeatedly. I'll never forget it.

/r/todayilearned Thread Link - livescience.com