It's kind of nuts that you go to sleep each night with no clue what you're going to experience in your dreams.
You could fly, talk to ghosts, or end up back in high school with a big exam coming up.
Dreams are so strange and mysterious that scientists have been exploring them for ages, and some of the facts they've uncovered are even weirder than the ones you already know.
Blind people have a mixed bag when it comes to their dreams.
According to National Geographic, researchers asked 50 people, half of whom were blind, to record their dreams for four weeks in a Danish study.
On one hand, many previously sighted blind people can see again in their dreams.
On the other hand, blind people have more nightmares.
While only 7 percent of the sighted participants reported nightmares, 25 percent of the blind ones did.
Their nightmares included things like losing their guide dogs or being hit by cars.
The researchers guessed that nightmares could be a form of "rehearsal" for real life and that blind people need more rehearsal because they experience more danger on a daily basis.
Research has shown that you can actually learn to control your dreams.
According to Deirdre Barrett, a Harvard-based sleep researcher, if you want to stimulate a dream in which you solve a problem, think about it before you go to sleep and try to create an image of the problem in your mind.
It's even better if you can use an actual visual.
For example, if you're trying to write a song, put your guitar next to your bed.
Or if you want to solve a problem involving a certain person in your dream, look at a photo of them before you go to sleep.
"Sometimes dreams make breakthroughs, and there are a lot of anecdotes about famous examples of major creativity or major scientific problem solving."
Not only can you control what you dream about, you can also control what you do in your dreams, in a trippy process called lucid dreaming.
There are a bunch of different ways to induce lucid dreams, one of which is called reality testing, according to a researcher from Stanford.
Part of reality testing is asking yourself throughout the day if you're dreaming, and then looking for clues that you're awake.
Looking for clues while you're awake today will help you become aware that you're dreaming tonight.
Helping you learn.
Do you ever indulge yourself and take a nap in the middle of the day?
If so, you now have a good excuse for dozing off at your desk.
Dreaming actually helps you learn.
In a study by researchers from Harvard Medical School, 99 participants played a video game in which they navigated through a virtual maze.
Afterward, half of them napped for two hours, while the other participants stayed awake.
Then they all did the maze again.
The participants who reported dreaming about the maze improved their performance over six times more than the people who didn't sleep or who didn't dream about the maze.
Acting out dreams.
Did you know that your muscles nearly become paralyzed when you sleep so you don't act out your dreams?
If that freaks you out, try this on for size: people whose muscles don't stop them from acting out their dreams are far more likely to develop neurological disorders like dementia and Parkinson's later in life.
In a rare condition called REM behavior disorder, people carry out the actions from their dreams while they're still asleep.
Take, for example, Mike Birbiglia, a comedian who writes about living with the disorder, who dreamed that a missile was headed for his hotel room.
He jumped out his second-floor hotel room window, both in the dream and in real life.
According to Time magazine, researchers at the University of Montreal studied almost 100 adults who had been diagnosed with REM behavior disorder.
They found that people with the disorder are 18 percent more likely to develop a neurodegenerative disease five years after their diagnosis.
Babies don't dream.
Have you ever looked at an adorable baby sleeping and wondered what they were dreaming about?
It turns out, they don't dream at all.
David Foulkes, author of Children's Dreaming and the Development of Consciousness, believes that babies spend their REM sleep building pathways in their brains and later developing language skills.
With all this brain development going on, there wouldn't be much brain-power left to also create dreams.
Children don't actually dream until they're 4 or 5 years old, when they develop the capacity to visualize imaginary things.
Even then, the dreams they report lack characters, memories, and emotions.
It's not until they're 7 or 8 and they have a sense of identity that kids' dreams start to include plot lines.
The stronger their self-concept is, the more vivid and structured their dreams become.
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