Enter two men. Man A is looking up at the sky. Man B is looking at the ground.
MAN B: I think we’ve been here before.
Man A points at a star.
MAN A: Look, there it is. The North Star.
MAN B: You don’t know that’s the North Star, it could be any star.
MAN A: No, it’s definitely the North Star.
MAN B: How do you know?
MAN A: Because that’s roughly where it was last night.
MAN B: We’ve walked miles since last night. We’ve moved, the Earth has moved, the Universe has moved, the stars have moved. Everything has moved since last night.
MAN A: The North Star hasn’t moved. The North Star is always in the north, that’s why it’s called the North Star. As long as we follow the North Star we won’t get lost.
MAN B: But you don’t know that’s the North Star. We might have been following a different star every night for all you know. We might have been going round in circles.
MAN A: But we haven’t been going round in circles, we’ve been going north. We’ve been following the North Star.
MAN B: But you don’t know that’s the North Star.
MAN A: Of course I do. That’s roughly where it was last night.