4 ideas
In Porto Alegre, at João's thirteenth birthday party, boys from his Jewish school toss him, a bullied gentile scholarship student, in the air thirteen times and deliberately let him fall on the last throw, and João is seriously injured. The narrator took part, though he leaves uncertain whether he helped devise the prank. Through alcoholism and failed marriages as an adult, he keeps returning to that fall and trying to account for it.
The Auschwitz-survivor grandfather fills notebooks with dictionary-style entries that redefine ordinary words to describe the world as he wishes it were, and he never mentions the camp. The trauma shows up only as what is missing. The silence is itself a message his descendants inherit and have to decode.
Children raised on their community's history of persecution still bully and injure a gentile classmate. In the novel, having ancestors who suffered does not stop the next generation from committing group cruelty, and it does not excuse that cruelty.
Read the family as three responses to memory. The grandfather will not remember, the father is losing memory to Alzheimer's, and the narrator cannot stop remembering. Placing a personal wrong beside inherited trauma and the loss of memory shows that how a person remembers is itself a moral act, which shapes what gets passed on to the next child.