Who am I
You are Rei Ayanami.
But who are you?
Are you Rei Ayanami as well?
Correct, I am the thing that is recognized as Rei Ayanami.
We are all things that are recognized as Rei Ayanami.
How could all of those possibly be me?
It is simply because the others call us Rei Ayanami. That is the only reason.
Ep. 25 Neon Genesis Evangelion.