After waking, it took me a minute or two to feel certain I would be safe. My bedroom was dark, but I was fairly certain that the things I'd just seen - grey-faced demon things, dead-eyed and with joints that moved like creaking wood - were not real. Most importantly, they were not going to split open their stitched-together faces and swallow me.
The downside of having a decent imagination is that when you have a nightmare, it's a doozy.
I don't have nightmares often. Usually, a bad dream for me is based on anxiety (apparently the most common emotion reported in dreams). When I was younger, these came in two flavours: A) I had forgotten to study for a test or B) I had forgotten to put on pants before going out in public. Sometimes the public nudity would take place while I was being given a test. Because my subconscious likes to save time and energy when freaking out, that's why.
I've stopped having type B, but type A has been replaced by dreams about missing deadlines.
Nightmares are different.
There's the just-falling-asleep dream of being chased, which ends with tripping over a root and suddenly waking up, limbs flailing. That's caused by a failure to be in full rapid eye movement sleep before the dreams kick off.
There are obvious scary dreams that are easy to explain to people. The dream about zombies with hollow eye sockets and rotting teeth biting out chunks of my flesh. The dream about being lost in a cave pursued by rats, only to find myself back home - until a rat the size of a Welsh corgi jumps off the fridge and latches itself to my face.
Then there are the nightmares that are just composed of a sense of dread over utterly nonsensical images. It's hard to explain why you woke up screaming "No! Not the Star Trek commemorative plates!" They just seemed. menacing, that's all. Patrick Stewart's head was shiny in a very alarming way!
The strangest nightmares I ever had involved geometry. No, not studying it in school. Lines and shapes. Straight, black horizontal lines on a white background. The lines would twitch and bunch up into black snarls, and I would wake up sweating, with a strange taste in the back of my mouth. I have no idea why I was so scared of these, but they recurred several times.
No one really knows why we have nightmares, because no one really knows exactly why we dream - which is part of the mystery of exactly why we sleep.
Scientists have chipped away at the edges of the nature of sleep and dreaming, but a century of research has led to the following two solid conclusions: Not sleeping and not dreaming is very bad for you, and everything Freud and Jung wrote was a steaming pile of nonsense.
Dreaming may (or may not) help us solve mental conundrums, firm up memories, or even help prepare us for waking life. I personally doubt the last idea, as I don't think I'll ever find myself taking a train from Canada to Europe, while playing Scrabble against Joseph Stalin and his army of singing goldfish.
Despite the odd nightmare, I actually like dreaming. I like the fact that my brain cuts loose and gives me a nightly dose of surrealism beyond anything Dali could imagine.
Nightmares aren't entirely bad. They've inspired art and literature from Fuseli's The Nightmare to Stevenson's The Strange Case of Dr. Jekyll and Mr. Hyde.
Even so, if anything I've written here about hideous, grey demons driven to smother you in your sleep gives you nightmares, I apologize.