Where Everybody's Crazy

I'm finding an awful lot of depth in Doctor Who of late, with lots of resurrection/mission metaphors:

Doctor: And this is a brand new planet Earth. No denying the existence of aliens now, everyone saw it. Everything's new.

Rose: And what about you? What are you going to do next?

Doctor: Well, back to the Tardis, same old life.

Rose: What, on your own?

Doctor: Why, don't you want to come?

Rose: Well, yeah.

Doctor: Do you though? I just thought, 'cos I'd changed...

Rose: Yeah, I thought 'cos you'd changed...

Mickey: You're never going to stay, are you?

Rose: There's just so much out there; so much to see. I've got to.

Jackie: Well, I reckon you're mad, the pair of you. It's like you go looking for trouble.

Doctor: Trouble's just the bits in between! It's all waiting out there, Jackie. Everything's brand new to me. All those planets, creatures and horizons. Haven't seen them yet... not with these eyes. And it is going to be... fantastic.

But after the mission, there's the whole reentry syndrome:

Sarah-Jane: You know what the most difficult thing was? Coping with what happens next - or what doesn't happen next. You took me to the furthest reaches of the galaxy, you showed me supernovas, intergalactic battles, and you just dropped me back on Earth. How could anything compare to that?

Doctor: All those things you saw, you want me to apologize for that?

Sarah-Jane: No, but... we get a taste of that splendour, and then we have to go back.