4 ideas
A person who cannot grasp what others want, and who is terrified of their anger, can stay connected to them by playing the fool. Because every exchange is a performance, the clown secures acceptance while making sure no one ever meets the real self. The act is itself a sign of alienation, and it deepens that alienation.
In middle school Yōzō deliberately flubs a jump at the horizontal bar and lands on his backside, and the class roars with laughter. Takeichi, a dim, sickly classmate, pokes him in the back and whispers, "You did it on purpose." Yōzō is so terrified of exposure that he befriends Takeichi to control him, and even considers wishing him dead. It shows how a façade turns anyone who sees through it into a threat to be managed.
When his friend Horiki warns that "the world won't forgive" his behavior, Yōzō realizes the reply is "Isn't it you who won't forgive?" Invocations of "society" or "the world" are often one person's judgment dressed up as an impersonal verdict. Seeing this shrinks the overwhelming abstraction back down to a specific person who can be answered.
Yōzō's young wife Yoshiko trusts everyone without suspicion, and she is raped by a tradesman she let into the house. The event shatters Yōzō, who asks whether trust itself is a sin, and it drives him into heavier drinking and then morphine.