Dreams

Last night, I didn't dream. But, according to scientists, you dream everynight; even if you don't remember it. So i began to ponder dreams. Here are some of my questions and thoughts:
What is a dream? What is its purpose? What exactly is happening?
The definition of a dream is a "succession of images, thoughts, or emotions passing through the mind during sleep". (http://dictionary.reference.com/browse/dream?&qsrc=)This means that a dream is random, nothing important, something that occurs "just because". They could be the unconcious emotions or thoughts from the day. Or perhaps they aren't random. Perhaps they could mean something besides the hollow leftover actions in the mind.
What if a dream was something to warn of something forthcoming in your life? What if a dream was images to counsel you of future hardships, joys, or dangers?
What if you there were identical copies of you in other dimensions? What if the dream you had at night is the day's events of someone, or you, in another dimension? Yes, perhaps dreams are just random or thoughts of your unconcious mind, but what if it were something more? There are so many possible answers to these questions, yet no one has any clue as to what the images and thoughts of dreams could mean.
In a dream your brain is just administering activity. It is doing nothing more than what happens when you are thinking during the day. Its nothing special. But what if it was...?