The Doctor: Grace, I came back to life. I held back death. Look, I can't make your dream come true forever, but I can make it come true today..
Grace: Tardis? What's a tardis?
The Doctor: A TARDIS is my ship that carries me through Time and Space. T-A-R-D-I-S. It stands for Time And Relative Dimension In Space.
Grace: Maybe you have selective amnesia brought on by shock.
The Doctor: Maybe. I don't remember.
The Doctor: The world's about to end, and here I am, stuck in traffic.
The Doctor: Wait, I remember. I'm with my father, we're lying back in the grass, it's a warm Gallifreyan night.
Grace: Gallifreyan?
The Doctor: Gallifrey. Yes, this must be where I live. Now where is that?
Grace: I've never heard of it. What do you remember?
The Doctor: A meteor storm. The sky above us was dancing with lights. Purple, green, brilliant yellow. Yes.
Grace: What?
The Doctor: These shoes. They fit perfectly.
The Doctor: I love humans. They always see patterns in things that aren't there.
Grace: Listen, why don't you just have a seat and open your shirt? I want to listen to your heart.
The Doctor: Hearts. Plural.
Grace: Right! Right.
The Doctor: You want dominion over the living, but all you do is kill.
The Master: Life is wasted on the living.
Grace: I finally meet the right guy, and he's from another planet.
The Doctor: The universe hangs by such a delicate thread of coincidences that it would be useless to meddle with it, unless like me you're a Time Lord.
Chosen answer: I've watched a surgeon perform open-heart surgery, and the radio was on the whole time. Whether music plays is probably up to the head surgeon for the particular operation, but it is certainly allowed.