Who's on What?

Ken: Hello
Lisa: Yes?
Ken: I was looking for my mind.
Lisa: Do you mind?
Ken: Yes, my mind?
Lisa: Really?
Ken: Yes, I've lost it.
Lisa: You certainly have.
Ken: Have you seen it?
Lisa: What!?
Ken: Have you seen my mind?
Lisa: My, my!
Ken: No, no, my mind.
Lisa: You're mind, you say?
Ken: Yes, my mouth seems to still be working, however the brain is no longer attached.
Lisa: Attached? Yes, I'm seeing someone.
Ken: That's nice. But have you, um, seen my, um, brain.
Lisa: Bran? Yes, that's a very good idea. Keeps you regular.
Ken: Brain! Brain!
Lisa: Go away, please. Come again some other day.