John Conlan refers to his parents as Bore and Hyper. They are over forty years older than him. His mother is obsessed with cleaning, while his father, a former alcoholic with heart issues, wants John to join him and John's older brother Ken at the Exchange. The Conlans seem exhausted by parenthood and annoyed by John's youthful imagination, wishing he were grown and out of the house. John, on his part, often validates their irritation. His dream of becoming an actor clashes with his parents' approval, and his flamboyant nature starkly contrasts with their conformity.

Lorraine Jensen's mother works as a nurse specializing in the care of terminal cancer patients. She steals from the families she assists and harbors a deep fear of men, likely due to her husband abandoning her years ago. Lorraine's insecurities are a result of her mother's constant nagging and harsh comments about her appearance. Lorraine's interests in writing and psychology stem from a desire to understand her mother and her own circumstances.

Norton Kelly, another significant character, is the same age as John and Lorraine. He enjoys stealing and being cruel, likely because he feels rejected himself. Although both Norton and John are outsiders, they despise each other. Norton plans to rob Mr. Pignati and wants to use John as an informant against the old man. Norton's anger over not being invited to the party at Mr. Pignati's house and his jealousy of John and Lorraine lead to the destruction of Mr. Pignati's pig collection. This act, more than any other damage caused by the party, severely harms John and Lorraine's relationship with Mr. Pignati, as Norton destroys the symbol of Mr. Pignati's love for his late wife.

Angelo Pignati, a retired widower, serves as both a parent and a child to Lorraine and John. He enjoys their company as if he were a child himself, eager to roller skate, play games, and tell jokes. Simultaneously, he acts as a parental figure, welcoming Lorraine and John into his home and offering them treats that their own parents deny them. Most importantly, Mr. Pignati trusts them and forgives them after the disastrous party.

Mr. Pignati's dual role as both a parent and a child highlights the theme of alienation between adults and children, which John addresses in his final narration at the zoo. John comes to understand that people must choose to be either a parent or a child, as the middle ground is highly unstable. By crossing into the realm of childhood, Mr. Pignati pays the ultimate price with his life. Similarly, John and Lorraine avoid adult responsibilities through their reckless, immature behavior. Consequently, the childlike parts of themselves perish alongside Mr. Pignati. They come to the realization that they must take responsibility for Mr. Pignati's death and can no longer evade accountability for their actions.

The grim implication of this truth is that the best moments shared by Lorraine, John, and Mr. Pignati occur when they are all living in denial. Eventually, these hidden truths begin to surface, despite the characters' attempts to ignore them. The resulting pain is intensified because these truths have been buried for so long.