From teeth falling out to flying, we all wake up remembering our dreams from time to time.
But why do we have these thoughts while we sleep in the first place?
Although scientists are yet to agree on a definitive answer, there are a number of interesting theories.
The above Ted-Ed video, created by Amy Adkins, explores just a few of the ideas on the topic.
Some researchers believe we dream in order to fulfil our wishes.
In the early 1900s Sigmund Freud proposed that while all of our dreams, including our nightmares, are a collection of images from our daily conscious lives, they also have symbolic meanings which relate to the fulfilment of our subconscious wishes.
Other academics believe we dream in order to remember.
Sleep has been shown to increase performance on certain mental tasks and according to the video above, dreaming while asleep improves our performance even further.
In 2010, researchers found that participants were better at navigating their way through a complex maze if they had dreamed of the maze prior to their second attempt. In fact, they were up to 10 times better at finding their way through the maze than those who remained awake between attempts and those who napped, but did not dream about the maze.
Another theory as to why we dream is that the process of dreaming keeps our brains healthy.
The continual activation theory is based on the idea that the brain must continually work in order to consolidate and create long-term memories. If it does not do this, it can not function properly.
In other words, our dreams may be a random screensaver our brain turns on so that it doesn't completely shut down.
As technology improves, our ability to understand the brain and why we dream may develop. But for now, we'll have to keep dreaming about these theories and many, many more.