Around 75% of dream content is negative. Nightmares generally produce fear, horror or anxiety in the person suffering from them; but can also consist of despair and great sadness.
Approximately one third of adults experience nightmares at least once a week.
On average, a person will experience a nightmare once a month.
The instance increases if the adult experiences fear in their waking life, stress or post traumatic stress disorder.
Nightmares can be caused by negative emotions in life, death of someone close, or even just sleeping awkwardly or having a fever. It is also suggested that eating before sleep increases brain activity and can trigger nightmares.
Recurrent nightmares with the same content can occur, especially with playback of events that may have caused PTSD.
A person experiencing a nightmare can wake up with no recollection of the dream, but a lingering sense of fear or dread.
…
The Joker didn't often take time off but he was tired and licking his wounds from the previous night. The Bat was unnecessarily harsh and out of character with his blows. His cuts and bruises stung when he moved and he was slower than he needed to be. So he called a time out.
It'd probably fuck with the Bat's head, anyway.
The Joker got drunk to numb the pain and staggered to his bed, tripping and stumbling over the things that littered the ground and stripping off his clothes, throwing them on the floor to join with the rest of the junk.
His flat was damp and dingy, but it did the job.
He fell face first on to the bed and was asleep almost instantly.
It was a couple of hours before he started twitching, his face pained. His hands scrabbled against the mattress, his fingers digging in, nails scratching. He twisted his face out of the way, images of knives and the memory of the taste of blood running through his mind and mouth.
He curled up into himself, shivering, and sobbed.
And then he woke up, the expression of horror melting into a frown of confusion. He ran his hand through his hair, his palms wet from the sheen of sweat covering his body. He relaxed, lying flat rather than cramped up in the bed and pulled the sheets that were tangled around his legs back up over his waist, still shaking from the cold and something that was unmistakably fear. He tried to relax his breathing and bring his heart rate back to normal.
But as much as he thought, he couldn't for the life of him remember what the dream was about. He figured one day that he would, and that day concerned him because that day he might regain some of his humanity and then what?
For now, though, the Joker resigned himself once again to not being able to sleep. He rolled out of bed and headed into the bathroom to drink some water and spit the taste of stale alcohol out of his mouth.
And then he'd sit in a darkened room and wait for the days to pass until he was ready to fight again.
…
Jonathan Crane knew fear.
He'd dedicated most of his life to it; understanding it, creating it, controlling it.
But he wasn't immune himself. Especially not now, after he was dosed with his own Toxin.
Sometimes when he slept the images would come back.
He'd be in a darkened corn field, no light shining down, the moon covered by clouds. He'd be calling out for Scarecrow because he was there to protect him, it was his job to stop them getting through, his purpose. Jonathan paid him in other peoples fear.
But he'd never be there.
And then he'd hear the noise of the crows. It would start with one cry, piercing through the night and then another would respond, and another, and soon the night would be filled with the sharp shriek of hundreds and hundreds of crows.
Jonathan would be rooted to the spot, hyperventilating with his heart beating in his ears and clammy palms crushing his head trying to keep the noise out.
And then the fluttering would start, the beating of hundreds of wings joining in with the cries.
And soon, they would appear on the horizon, their red eyes shining against the night, but Jonathan wouldn't be able to run. He'd have to stand and watch them get closer and closer, his voice giving out on him as well as his legs.
The field would turn red with blood with their approach and Jonathan would watch it coming powerless to do anything.
Scarecrow would always take over and wake him up just as the beak of the first crow was about to pierce his flesh and he'd come to shaking and crying and feel thoroughly pathetic.
Scarecrow would reassure him, calm him down, help wipe away the tears and rebuild his fractured ego.
Jonathan would be left even more desperate to control fear.
…
Bruce had nightmares almost every time he slept.
The subject matter would change; his parents deaths, his fights, bats, Rachel, red, laughing mouths with foul teeth, a mask with big blue eyes, bats pouring out of it and flying at him…
Being Batman wasn't good for his day to day life, but his sleep patterns had always been terrible.
He was now so used to waking up scared that the fear dimmed into nothing and he managed to get back to sleep after an hour or so. But through the day he was tired and irritable, even moreso at night when he'd pummel criminals into the floor with even more vigour.
He tried to forget about it but sometimes, when he was lying in the dark under expensive sheets he'd be hit with a wave of despair and wonder why the hell he bothered.
Sometimes, he'd give anything to be like those he fought, assuming they slept well at night with a clear conscience because really, he never saw beneath the masks.
The Joker and Jonathan assumed the same about him, never seeing beyond the makeup and the cowl.
Underneath it all, deep down, they were all the same.