When we die, all of our memories are transferred into a new form. Our core ideals and our identity. Sometimes, as in the case of my brother, we can control the regeneration so that there's hardly a difference.

If it's under traumatic circumstances, however, we practically become another person. The Doctor with the scarf? He used to be me. I came here as I was about to regenerate.

[He's just straightened everything out for her. Maybe he- well, maybe he shouldn't talk about it. Not for his benefit, for hers.] You know, I believe I'd like a drink.