I've had it before and it was actually more annoying than scary. I even had a hallucination with it, I saw a shadowy figure standing in the doorway to my room. rather than being scared I was just annoyed and frustrated that they weren't closing the door and I couldnt get up to do it myself. It was like reality and dream logic were weirdly combined for a while.

When it hasn't happened in a while (or it's one of the first times) you can forget in the moment.

It's like swimming under water and realizing you are running out of air so you start to surface, but something wraps around your foot and you can't go up anymore.

Almost everyone feels panic at this. Your brain and body try to fight, your heart is racing. It's the terror of being trapped in the dark, not knowing what caught you.

With that type of terror most people don't think to just go to sleep and the problem will go away. We panic and struggle.

Imagine that feeling, except you can breathe (usually) but you are trying to scream, to move any part of you and fall out of bed, or to get someone's attention so they'll help you. But no one hears you, they stand near but don't help, and you realize you are paralyzed. Bonus points if you can see and hear them (while in reality no one is there and your eyes are closed, but you don't know this yet)

You don't know if what is happening is real. It seems real.

Are you really paralyzed or is it a dream? If you go to sleep, will you wake up back to normal, will you die, will you wake up later still paralyzed? You want to cry because you can't remember enough of yourself to be sure what will happen.

Time is distorted. This could be mere seconds, minutes, or hours. How long has it been?

If pink elephants in silver tutus start smoking pipes and debating the best cheeses, you feel relief. For me, the sleep demon showing up is a relief, because the brain starts to calm down and think wtf, this is a crazy dream.

At this thought you finally snap awake.

Hopefully next time you can realize sooner and control it.

It's not a feeling that you can rationalize by looking at It from the outside.

It's a primal and visceral feeling, a fight or flight situation. Sometimes you even think "hey this is a sleep paralysis, I can just ignore and go back to sleep", but you usually can't, and your body screams "danger, danger, danger, run away, fight back", but you can't move, or scream, or "wake up". It bites of our instincts, and It's hard to describe afterwards, but you wake up scared and bit relieved that you're alive.

It gets worse If you hallucinate, all sorts of distorted figures and creatures appear, all fabrication of your brain of course, but since you're half awake, they are half real as well, you can feel their presence like a sixth sense, when you look at a dark corner or a dark hallway and you know something is lurking there, sometimes you can even "touch" them if they come near enough.

I had and episode one time that I had to keep pushing a floating demonic mask away from me, I could only move my right wrist, and yes I could somewhat touch the thing, and I had this primal fear that If that thing approached my head, I would die.

It's a really hard concept to describe, but once you experience It, you never forget the feeling.

For me, I get extraordinarily scared. I'm not in the same state of mind, at all. Emotions build up fast and intensely. I did get used to it though. That's what I do, keep eyes closed, try to keep calm, and ignore the weird sounds and weird sensations.

I knew what it was, but I was panicked and unable to calm down before it passed. I was deeply affected by not being able to move anything. I imagine other personality/neuro types would handle it differently, but I did not care for it.

That said, I get being curious about experiencing something benign but possibly scary.

But if you know, isn't it mostly annoying, like you want to move but can't?

Not really. Not being able to move while you feel threatened is a very primal kind of fear, so it's hard to rationalize your way out of it even after you realize what's going on.

But knowing what the cause of it is does help a little bit. It doesn't get rid of the intense fear, but there is a relief you feel knowing that there's a way out (assuming you know your body well enough to know how to reliably wake yourself up).