Sophie is motivated by two competing desires: to live her life fully while escaping any memories of the past, and to punish herself for the actions she took during the Holocaust. The first desire motivates her enthusiasm for sex, heavy drinking, and love of music, good food, and fun. Sophie has experienced hellish suffering and has been fortunate enough to get a second chance at life, including the opportunities and pleasures that life in America offers her. She wants to enjoy whatever she can and also use this pleasure to distract herself from painful memories. At the same time, Sophie is tormented by a profound sense of shame and guilt. She believes she committed evil actions both before and during the Holocaust, and she does not think that these actions were justified by her desire to survive. When these feelings of shame and guilt surface, Sophie becomes consumed by self-loathing and despair. She is attracted to Nathan because their relationship feeds both of her personal motivations. Being with Nathan allows her to sometimes escape from her past by focusing on pleasure, but when Nathan lapses into his darker moods, he offers an opportunity for her to punish herself by accepting the abusive way he treats her.
Sophie’s motivations remain consistent throughout the novel, but her focus gradually shifts toward a preoccupation with guilt and self-loathing. In her conversations with Stingo, Sophie slowly reveals more and more about the truth of her past. Sharing this information prompts her to become more haunted by it. Sophie is not capable of leaving her past behind in order to build a new life for herself. When she has the chance to end her relationship with Nathan, she is eager to be reunited with him, and when Stingo offers her the chance of a fresh start in Virginia, she becomes obsessed with reminiscing about her past and all the memories that haunt her. When Sophie flees back to New York to meet Nathan, she succumbs to her motivation to punish herself. Her suicide represents the end of her struggle to move forward and build a new life for herself. Instead, she decides to enact the ultimate punishment.