Our hero was not one of those Dominican cats everybody’s always going on about — he wasn’t no home-run hitter or a fly bachatero, not a playboy with a million hots on his jock.
-- Yunior (Part I, Chapter One, The Golden Age paragraph 1)

Importance: Yunior starts the novel with a description of how non-Dominican Oscar is. This is significant because it sets up the idea of how unusual Oscar was in comparison to other Dominicans and how he stood out in comparison to them.

It truly was a Golden Age for Oscar, one that reached its apotheosis in the fall of his seventh year, when he had two little girlfriends at the same time, his first and only ménage à trois. With Maritza Chacón and Olga Polanco.
-- Yunior (Part I, Chapter One, The Golden Age paragraph 7)

Importance: As an adult Oscar is afraid that he will die a virgin. As a young boy, however, he actually had two girlfriends at one time, the high point of his love...