There is a reason, subconscious or conscious, that several of Sam's closest friends in Milliways are or are approaching immortal; the appeal of people who won't leave him has never yet gone away.

(Of course, sometimes even the people who don't have to leave him do, anyway.)

But it seems that old habits die hard, and he has retained that affection for humans that he had when the alternative was millennia of loneliness. Cal, in particular, has been good at unintentionally shattering Sam's defences.

He blinks, though, at the sudden change in subject.

"Hmm? Only in my world. Why?"