She's not afraid. She's wearing a dentata.

Having a persistent nature is part of being human. Otherwise we wouldn't be able to speak of knowing another person, or loving them, or being their friend or enemy or rival.

"Sorry," she said, "I got out as fast as I could, but I had to stay and socialize. Protocol, you know." "Explain protocol," Nell said. This was how she always talked to the Primer. "At the place we’re going, you need to watch your manners. Don’t say 'explain this' or 'explain that.'" "Would it impose on your time unduly to provide me with a concise explanation of the term protocol?" Nell said. Again Rita made that nervous laugh and looked at Nell with an expression that looked like poorly concealed alarm.

Of persons I will say this: it is difficult to tell when they are running aright but easy to see when something has gone awry.

A few dud universes can really clutter up your basement.

Humans needed water or they would die, but dirty water killed as surely as thirst. You had to boil it before you drank it. This culture around tea was a way of tiptoeing along the knife edge between those two ways of dying.

We see everything from the narrator's point of view, so exposition about the world is limited to what impinges directly on him and the story he's telling. Considering how old the world is, we learn very little about its history, which I think is a good thing.