“We dream as a grounding tool.  Waking life is already so dream-like that, without an alternative state to call “dreaming” we would lose track of what is real – like the movie “Inception”.  Dreaming may have been evolved is an adaptive trait so that we do not go insane.  Or, it may have been devised by a higher power of some sort in order to keep humans believing that ‘reality’ is all there is, since it is more conscious state than dreaming.”