Have you ever had a dream that was so vivid and so real that you became certain this iteration of reality  was not the only one you have existed?

You become certain that there are parts of you that carry prehistoric identities and memories because some of the specificity of the details of this dream. Additionally, in this dream you are both watching as yourself and you occupy a "character" and play a role in the dream. The moment you wake you can still see, feel and smell the surroundings of your dream momentarily until you fully awaken. Me neither! ..