apparently dream sharing is not as uncommon as you may think. it is also to note, some of the dream characters you experience are someone you know,(but disguised/or looks different as someone else you may or may not know) and not an aspect of yourselves. i dont really know why this happens, but i think it is to do with the intent or state of the other person or your perception of them at that time. this especially relates to precogs/information purposes.