I have a recurrent nightmare that I have to interface with a computer network protocol that is written to use little endian, with named, variable-sized fields and no schema.

... Programmers might not be human.

Wowza. That's an intense nightmare.

When I was a kid, I had this one recurring nightmare. It always started with this intense sense of urgency. The task I had was always slightly different, but it always gave me the sense that if I failed, the world would die. Every single time I had this dream, I failed in the task and I knew it. Right before the dream would end, I'd walk outside, sit down on a picnic bench and watch birds flying through the sky. Then a bright flash would happen in the distance and I'd wake up drenched in sweat. I didn't understand it as a kid, but now I realize it must have been a nuclear explosion. I fail at disarming a bomb.

Fortunately I'm a welder, so there's not much chance I'll end up being responsible for nuclear holocaust lol.

Jesus Christ dude, that is definitely a nightmare. I used to have a recurring dream that was pretty scary but I am not sure I would call it a nightmare. I am not sure I have ever had a nightmare.

The dream was recurring in theme but the scenario would change. It started about grade six when my friends and I would have contests to see who could jump off the playground swing to go the farthest. My dream would be that I would jump and then realize I had severely underestimated and would be very hurt when I hit the ground. That theme continued with going over jumps on bikes, skiing, snowboarding, motorcycles, etc.

But I never once hit the ground. I would wake up a split second before I did. I am pretty sure it was an unconscious fear of biting off more than I could chew, getting in over my head, etc. The fact that the dreams stopped when I graduated from law school and got called to the bar reinforces that belief.

But now let me tell you about my favorite dream. My girlfriend came to visit me my first year in university. I was apparently having a dream where I was crawling though the desert in search of water to save the 2 of us. I climbed a huge sand dune, saw an oasis and turned around and yelled "This way. There is water this way!" To which she replied "What are you doing?" Then I woke up and realized I had gotten out of bed and had climbed up upon my desk. <insert shrug ascii>

The worst I ever had was when I was a young teenager. It was a very slow moving dream of just a man walking down the hallway toward my room. It was very dark so all you can see is his silhouette, it was a very classic noir-bad-guy silhouette with a fedora and everything. He walked slowly down the hall, but instead of entering my room he turned at the last minute and enters my little sisters' room. Then I woke up I freaked out and ran into their room and basically collapsed into tears because I was so glad no-one was in there with them. I ended up sleeping in the hallway the rest of the night.

Also I still have a reoccurring nightmare about being chased in circles around a coliseum by lions. That one sucks.

I had one not too long ago where I had left a skate park where I had a lot of fun with some friends. Just outside of the park was a telephone pole with some wires that weren't connected to another telephone pole so they we're just left hanging downward. At the top of the telephone pole were 3 kids. An older brother and two little kids, one little girl and one little boy. It was obvious they were going to start climbing down, and I realized it was dangerous but kept walking anyways. While walking under it, all of a sudden there's a extremely loud buzzing sound above me. Around me full limbs, pieces of flesh, and tons of blood fall all making a memorable splashing noise. Horrified I looked up and saw the other two kids staring at their older brother, screaming and crying. They cried out for their mom who was on the ground, crying out for them as well. The little girl tried to go down the wire real fast. The same thing that happened to her older brother happened to her. Blood and limbs everywhere. The little boy seeing this, who was just in absolute despair at this point, looked at the ground and just leaped off. I can't remember leaving on any Tarantino movies while I slept, because that landing was gruesome as well. From there I just ran down the road that lied front of me, at the same time covered in blood. I didn't know what to do so I just started screaming. Loudly. Eventually I got so dizzy that I just puked then passed out beside the road. That's when I woke up. The first few hours of being awake I still felt shooken.

I have a very poignant falling dream every so often. It's nothing but falling really far and coming absurdly close to hitting the ground, with time slowing down asymptotically as I approach.

I had one recently that more just really bothered me rather than 'jump scared' me, and involved me being in a car ride with my family, and absolutely everyone was in seething rage mode, taking any single slight opportunity to launch into full-on rants with each other. And this rage felt so real, even 'my' rage felt strong. It really made me think on some of my own anger that I have been repressing lately, and makes me want to look into better ways of releasing it instead of bottling it up.

I occasionally get scary dreams, but I usually find those amusing once I wake up. There are only two types of nightmares that actually really fuck with me.

The first is the nuclear apocalypse dream. I'll be doing something routine like walking through an airport when all of a sudden there's a flash of light and something erupts on the horizon. The one thing all of these dreams have in common is the gut-wrenching feeling that something has fundamentally changed, and would never return to normal--not just something within me, or my life, but life itself. The bottom drops out of my existence and sense of reality and the realization that it's all over sinks in. Then at some point I wake up and I'm left with an empty feeling for a few hours until I distract myself with breakfast and the internet.

The other dream that really fucks me up has to do with something irreversible happening to someone close to me. I had one dream that I was with my sister at my house, and I get the idea that I should test my stereo by playing it at full volume and then seeing how far I could walk from my house and still hear it (I did this back in high school when I bought a surround sound logitech system--the subwoofer extended about three doors down my street with my door shut). Suddenly I realized that I should have been watching my sister, and a car screams by with its side door hanging open and I see that she's been kidnapped. After chasing it down the street, it drives out of reach and I realize that I'll never see her again.

One other of this type of dream involved my family and I watching TV at my dad's apartment on the top floor of his building. Next thing I know, there's a massive shaking underneath us and the building starts to undulate. We somehow make it up on to the roof, and as we do, the building bends to a breaking point and begins to fall over. Just as my family and I are coming to terms with our demise, I wake up and am left sitting in bed wondering what hell is wrong with my brain for it to subject me to that kind of emotional turmoil when I'm trying to rest.

One thing I find comforting about fantastically violent nightmares is that they're so otherworldly that I have no trouble compartmentalizing the emotions I experience. The weirder the situation, the quicker after waking up I'm able to view the experience like someone sitting in a theater watching a horror movie. It's the realistic situations that I find the most troubling, because they could very well be real emotions and they don't quickly fade once I wake up. I feel like somewhere deep down, some part of me knows what it would feel like for my life to be completely ripped apart.

EDIT and for the sake of answering your question and not getting completely off track, the nuclear apocalypse dream is by far the worst.

Preface: I usually have some weird ones, but this one woke me up with a thudding heart:

I was only a spectator, so viewing it from a third person point of view; as a dreamer I can't act on anything consciously, but the emotions I could feel were "real" and sometimes can progress the dream along the way. There was a prison facility for the most demented and mentally unstable criminals everywhere in that planet carved into a naturally occurring cave. It had a jagged entrance, like the maw of an wrathful beast waiting for the most opportune time to snap shut the pathway to freedom. The cave walls were a sandstone colour, but far dirtier and yellow, the colour of a man wasting away with jaundice. I felt myself in this dream world being dragged into the depths of this horrid prison. Outside there was bright light, which I assumed to be a desert, but inside was bitterly cold and wet. If I could have had a light, or remembered more clearly, there most definitely would have been slime dripping off the walls- this was not a happy or welcoming environment. Yet that was not it. I was suddenly shifted into this horrific scene, with knowledge suddenly burgeoning in my asleep mind. There was a pale, emaciated, and naked man chained down onto a part of fencing in a pitch black cave room. Dirty, murky water roughly a few inches deep submerged his limb's extremities, and likely have rotted it through in most places. The chain fencing was rusted, and obsidian black in the places that remained with the original colouring, resting partially in the water so that he was only half submerged. The person was clearly delirious, eyes rolled back, and I instinctively knew that he was drugged or not right in the mind, but the most revolting part was that I knew the people here wanted something from him. His lips. They were considered a delicacy, and sure enough, a naked woman with even paler skin soon entered my frame of mind. Her hair, matted with grease and water, would've soured milk, but it was her spider like crawl towards that chained man that had me most horrified. She walked, hands and feet through that cold murky water towards the man, crooning "aaaahhhh yesssss" all the while, and when she had reached him, she pulled out of piece of jagged metal that also was rusted in parts and began slicing off his lower lips.

Blood flowed down the man's chin, but he seemed not to care and he thrashed feebly on his bindings. Slowly severing his lips, the woman began crowing in a sing-song, baby like voice, and as the lips began to separate from the man's mouth area, she slowly began to moan in pleasure like an animal in heat. The moment the lips were cut off, she released a gasp, "ahhhhhhhhhhhhhhhhhhhhhhhh yeeeeaaaah" and slip the piece of bloodless lip into her mouth as one would do to a spaghetti noodle, her body convulsing in an orgasm as it went down her way too white esophagus...

Then she turned her head completely around and stared directly at me and SMILED.

I used to have massive, vivid, terrifying nightmares. From childhood until mid to late twenties. Started having less of them once I started working through stuff, and now generally only have anxiety dreams of varying strengths.

Common, memorable elements of the nightmares included: sleep paralysis, sexual abuse scenarios, terrifying cult-like figures, running for my life, brain losing capacity for speech and voice getting caught up in something twisted, confusing I couldn't control, being pursued, something wanting to hurt, kill me, being covered in blood, crowd looking up, metal fragments embedded in skin, religious transcendence over the pain and violence, mind breaking apart, going insane, losing the thread of reality, heavy bodies on top of me and i can't fight or stop them, and so forth.

There was a period in my life during which, for some reason, I started experiencing sleep paralysis.

One afternoon I woke up from a long nap and I couldn't move. I felt like I was literally going to die. It's a strange feeling and I'm not sure how I would describe it to someone who's never felt it. Try to imagine that someone is holding a gun to your head and could pull the trigger any moment.

I didn't see or hear anything, but I could sense a presence, located somewhere above my head. Whatever it was, it was the source of my fear. It's like it was emanating this strong killing intent.

I knew it wasn't real because I'd experienced sleep paralysis before, but even knowing that, it was overwhelming. As soon as I could move, I got up and ran out of the room.

I had a lot of nightmares and I didn't want to go to sleep as a small child - but I blocked the memories out, and now I can't remember my dreams or lucid dream..

Two that I can remember are:

There was one where I didn't see anything scary, just felt complete stress, stuck in an underground labyrinth, yellow glowing walls with dark symbols on them.. trying to get out...

Another one was very vivid and I can remember it.. though it wasn't the worst at all...

I'm in a church, similar to one I have been to, but it seems foreign. There are a few people inside focused on the preacher, but I'm gazing sideways at the solid dark wooden pews, out through the gothic windows. The outside of the church is actually my home-church parking lot, and as I look out the window; I see a figure zoom by halfway up the window, down the length of the outside of the church. It's a typical looking witch, flying on a broomstick. (I was born in 1989, this happened before HarryPotter existed); I run the length of the church toward the back where the entrance is, but before I know it, mind racing, filling with fear I am caught by the witch, I am lodged under a large circular saw, and it is currently running, being slowly pressed down through the middle of my body, rending me in twain.

I wake up.

Besides the odd bouts with sleep paralysis, the one nightmare that really gets me is quite a silly one - it was originally a fever induced nightmare I had in India and it has revisited me many times since. It just consists of me running on train tracks - I cannot escape them at all - as a train a hellish looking engine chasing after me. I usually see myself running as though I'm playing a third person video game - I'm just a floating head, observing everything. The sounds in particular are terrifying...Like I said, really it is just quite silly!

It all started in a rustic house that was a mix of two previous housings I was in and a generic wooden shack. We were in the city's suburbs. Me and my sister are playing in the backyard-which-happens-to-be-next-to-a-street (which is a configuration that was seen on one of the streets I lived on), when my best friend rammed down the fence with a green 70's muscle car (mighta been a Chevy) and wearing a frog suit. He hands me one, and tells me we're going shopping. I wave my sister and father (who was sitting on the porch watching us). Cue timeskip.

When I come back, both of them are inside. But there's this black... mold thing growing on the house. And when it peels back, it looks like lava underneath. Like a dumbass, I try going inside - through a short vent because the door was also moldy, and I look down the hall - it's growing everywhere, and my house is extra decrepit. There configuration was as follows: there was a main hall going straight to the front door (and that area was completely clogged with a plug of the mold). From my position, there was rooms, in this order - right, room. Right, room. Left, bathroom. Right, kitchen. Anyway.

I peer into the first room. I see what was my mother... was. She was covered in the mold. In panic, I continue to the next room - my father and sister were laying on stretchers. My sister was being digested alive by the stuff, and my father was already mostly eaten, and his bones were sharp... Pretty much like they'd been turned to obsidian. I continue running down the hall, to my bathroom - and a blob of the stuff falls on my head. I look at myself in the mirror, and try to rinse the mold off - but all it succeeds at doing is making me watch myself melt.

Then I 'wake up'. The apartment is different. But oh well, it could be sleep confusion. I get ready to school. Timeskip. I head for science class - but there's a taped off area at the end of the corridor. Like a dumb shit, I go investigate. A full classroom, dead (and to the point of being dessicated). All laying on their desks... until all of their heads flip to look at me with glowing yellow eyes. I panic, turn around and start running... and of course trip. The floor feels like a tar-coated rubber carpet as I try to crawl away (without success) from the classroom. A friend picks me up, asks me if I'm alright and we actually DO manage to run away from it. Timeskip to lunch.

The cafeteria looked like the one from a school I only visited (not attended) a long time ago. Except everything outside is dark. The students are talking in hushed voices. Not bothering, I head to the locker room to pick up my lunch. (Don't question it).

The locker room was like a distorted version of the one in the school I attended for most of my high school experience. That locker room had a raised platform with locker rows, then more lockers the other way, in depth. Except that this one, the room was bulging - the lockers were assembled in curves, like space expanded in the middle of the room. Also there was lounge materials. I don't think twice, go back to class. Timeskip.

I return to the locker room. The lights are half-functioning, and it's dusk outside. There's two dead bodies on the lounge stuff - one on a recliner, the other on the table. I ignore it, go grab my stuff, students pour in. Then it happens.

The bodies raise. And they start killing people. With guns somehow. And the killed get guns too and kill more people. As that happen, I sorta start floating and I'm forced to watch the carnage as the floor of the locker room turns into a laughing face.

Then there's an alley. In the alley, there seems to be a dead dog. I find myself in a detective's office, reading a report from a cabinet. It goes back and forth from the pictures and report - like a bad, creepy sitcom. I get more info. "Was murdered by stabbing." "Was a mid-20's woman". "Was wearing a red dress". Every time the corpse gets more vivid with details until it gets up.

I wake up for real this time. Except not. I'm in my room. There's the corpse, complete with yellowed skin and blood splatters, crawling out of my wall with a knife ready to stab me. Until I manage to move my pinky toe which breaks my sleep paralysis. I feel dread. I stay there, on my bed, motionless, for god knows how long - the only thing that I could use to tell the time was the ticking of the clock. When the ticking stopped being audible, I end up leaping away from my bed (using my bedroom door as an impromptu brake) and turn on the light before leaping back to my bed and laying there, in the light, until my mom comes and check up on me because she saw light. Since I'm not sleeping for that night, I get on my computer - turns out to be 3:30.

Did I mention that, at the time, we only had silent, digital clocks?