Nights in Yong’an City were full of animal cries of no discernible origin. I was born here, and got used to it early on. My mother used to tell me, ‘You can’t be sure that beasts aren’t people, or that people aren’t just another type of beast.’ But that wasn’t how things were. People would always be scared of beasts.
-- Narrator ("Sorrowful Beasts")

Importance: The narrator's mother teaches her much about beasts when she is a girl. This quote is important because it foreshadows the revelation at the end of the novel that reveals there is no difference between humans and beasts at all.

Every beast has a beastly nature. At the full moon, human children ought to stay at home. My mother would say, ‘The beasts all want to eat people, just as people eat them.’ Mutual destruction is the only way to survive. That’s the circle...
-- Narrator ("Sorrowful Beasts")