DOCTOR: I'm not running away. But this is one corner of one country in one continent on one planet that's a corner of a galaxy that's a corner of a universe that is forever growing and shrinking and creating and destroying and never remaining the same for a single millisecond. And there is so much, so much to see, Amy. Because it goes so fast. I'm not running away from things, I am running to them before they flare and fade forever. And it's all right. Our lives won't run the same. They can't. One day, soon maybe, you'll stop. I've known for a while.