Jiyoung was starting to feel like a stranger to Daehyun. After all this time—the stories they shared, as countless as raindrops, the caresses as soft and gentle as snowflakes, and the beautiful daughter who took after them both—his wife of three years, whom he married after two years of passionate romance, felt like someone else.
-- Narrator ("Autumn, 2015")

Importance: When Jiyoung begins impersonating other women, Daehyun is confused and terrified. This quote is important because it shows how rapid Jiyoung's transformation seemed to Daehyun, who was never privy to her innermost thoughts and feelings.

Jiyoung’s mother would praise the girls for taking good care of their brother and not competing for her love. Jiyoung thought it must be the big age gap. The more their mother praised, the more impossible it became for Jiyoung to complain.
-- Narraator ("Childhood, 1982-1994")

Importance: When Jiyoung's younger brother is born, the whole family starts to revolve around him and...