Me.
Me is I. I am Me. I am the one that I know directly. I feel my own feelings, have lived my own history, and know my own knowledge. It is easy to communicate with me because I have already said it.
At the same time, I am a mystery unto myself. If anyone understands me, I do; yet I am confused and lost within myself.
You.
You are you. You are not Me. I am not You. You are the one that I do not know directly. I know You through my ears, through my eyes, through my skin. Everything I know about You, I learned through my own perceptions and knowledge filters. I cannot know You directly; my consciousness will never be Your consciousness (at least not literally).
You feel Your feelings. You know Your knowledge. You have lived Your history. I only have as much access to these as You are willing to grant; but first You must know Yourself.
We.
I and You are Us. We are Me and You. We are the intersection and union of Our knowledge, Our feelings, and Our history.
We are what We become.