Dreams are mysterious and hard to study. However, there are some things we know about the brain after we have shut our eyes.

1) Lucid Dreaming

This is where you are in control of your dream. There are several techniques you can use to achieve this. When you train your mind to become aware it's in a dream, you can choose to direct your dream in any way you want, like flying or time traveling. Some people even say mastering lucid dreaming is helpful for overcoming fears since you can choose to face them while you're asleep and feel safe.

2) R.E.M. Disorder

Most people experience R.E.M. sleep every single night. This is the stage of sleep where the body is paralyzed and is in the deepest form of rest. Some people are unable to reach this stage of sleep and they act out their dreams. There have been cases of broken limbs and broken furniture.

3) You can't read or tell the time

It seems to be almost impossible to read something in our dream. Our minds won't hardly allow it. Lucid dreamers report that every time they look at a clock, the hands don't appear to be moving.

4) You dream every night

Lots of people claim to never dream but that is just because their brains don't remember it when they wake up. Talking about a dream as soon as you wake up helps you to remember more of it later on. If you never bring it up, it can escape your memory.

5) You only dream of faces you have seen before

Apparently if youdon't recognize someone in your dream, your brain had previously stored the image. When you fell asleep it pulled it out to place in your dream. You never knew it was there to begin with so that's why you think it's a stranger.

6) Sleepwalking

This is a rare and dangerous form of R.E.M. disorder. It's a step further than just acting out your dreams. You can actually get up and travel around as if you were fully awake.

7) External stimuli

While sleeping, your mind can incorporate external noise into your dream. For instance, if there is a loud sound coming from the TV, an airplane may appear in your dream. It's as if your mind can't decipher between reality and fiction so it blends the two.

8) The blind can dream as well

If a person became blind after birth, they will still dream in the same way we do. However, if they were born blind, their dream won't involve images but instead the other senses.

Dreams may be unpredictable but researchers say they can be helpful for memory consolidation or conflict resolution, and mood regulation.