You're a human, aren't you? Or were, once upon a time. You lot always get so muddled on that idea. That [he gestures to Jack] isn't you, any more than this [he gestures to himself] is me. Or this, or this, or this, or this, or so on, you get the idea.

[He's quite serious at this point, and as he speaks his form flickers to a gargoyle, then to a bull-headed minotaur with dripping fangs, then to a small greco-egyptian boy, then to a slowly rotating luminous orb, before settling down as a slinky desert cat, whose tail wrapped around its legs as it settled primly down.]

It doesn't change who I am and what I can do, what I look like, any more than it would change you. You won't change just because someone happens to look like you either. But you all do it.