My plan was to never get married. I was going to be an art monster instead. Women almost never become art monsters because art monsters only concern themselves with art, never mundane things. Nabokov didn’t even fold his own umbrella. Vera licked his stamps for him.
-- Wife (Chapter 2 paragraph 11)

Importance: The main character expresses her dreams very early on in the book. This is important because the fact that she never follows her dreams is the main driving force for her depression later on in the book and addresses one of the main themes of the story.

He gave me a CD to take home. On the cover was an old yellow phone book, ruined by rain. I closed my eyes and listened to it. Who is this person? I wondered.
-- Wife (Chapter 3 paragraph 6)

Importance: The protagonist meeting her husband sets up the rest of the story, and the cd is what initially makes her interested in...