I sometimes wonder what was disappeared first—among all the things that have vanished from the island.
-- Narrator (narration) (chapter 1)

Importance: This line of narration is the first line in the novel. With this line, the novel immediately begins building the world of the story, in which the Memory Police have the power to erase people's memories of certain objects, effectively making those objects 'disappear' from the island and the lives of the islanders. the somewhat passive tone of this line counterpoints the fundamental horror of the situation.

They took four people from the center of town, in broad daylight.
-- Narrator (dialogue) (chapter 4)

Importance: The narrator makes this statement during a conversation with R. The narrator is commenting on the fact that she recently saw the Memory Police arrest four people in the center of town, in the middle of the day. The other townspeople are aware that the Memory Police will likely kill those people. This situation...