The thought of that – that fact of it – that she, Raymie Clarke, was without a father, made a small, sharp pain shoot through Raymie's heart every time she considered it.”
-- Narrator (chapter 1 paragraph 32)

Importance: This is very early in the novel and gives the reader the information that Raymie's father is gone, that he chose to do so, and that Raymie is hurt by the situation.

Just that. 'Good-bye, Raymie.' Why did those words matter so much?”
-- Narrator/Mr. Staphopoulos (chapter 10 paragraph 18)

Importance: Mr. Staphopoulos said the words “Good-bye, Raymie” as he was leaving town for good. Raymie notes that he did not say anything else but the words had a powerful effect on her. This is one of many examples of Raymie's abandonment issues and how they affect her outlook, even on events that took place before her father left her.

Every day in Lifesaving 101, Mr. Staphopoulos had all the students stand on the dock and flex their...
-- Narrator (chapter 13 paragraph 2)