3. You were seared onto my heartsIm running to you, and Rory, before you fade.

The Doctor never stuck around with any of his companions as long as he did with the Ponds. And the reason for that is that, while the Ninth and Tenth Doctor needed a companion with them, the Eleventh Doctor is dependent on his companions. They dont necessarily have to travel with him all the time, but he needs them, because they are family. Everybody knows that everybody dies, but Eleven accepts it far less than any other Doctor. He knows that Rory and Amy will fade, but he cant face the end. Its in this scene that we understand why the Doctor couldnt convince himself to let Rory and Amy go, or to push them away. He knew the facts, knew that age and death were coming, but like a child he refused to accept it. And who can blame him, when he shows here how much he cares for his Ponds.