"Holding onto material things means other things get left behind," the Doctor countered, "And I haven't got much in this world. Even less place to put it all."

Not that Reinette's homes were not large, but they weren't the same. There was no movability. No way to take it all with him. That was what the TARDIS was, it was freedom. Freedom to hold onto memories and take them all with him.

He placed a hand on her forearm, trying to imagine that he could give her warmth that way.