The Doctor: Ashildr.
Me/Ashildr: That's not my name. I don't even remember that name.
The Doctor: Well, what do you call yourself?
The Doctor: Yes. You. There's nobody else here.
Me/Ashildr: No. I call myself, Me. All the other names I chose died with whoever knew me, Me is who I am now. No one's mother, daughter, wife. My own companion. Singular. Unattached. Alone.