* When Ponyboy first meets Johnny: Johnny is immediately put down by the Socs, and Ponyboy witnesses the humiliation. This sets the stage for Johnny's later actions and how he feels as an outcast.
* After the rumble: While the Greasers win the rumble, Johnny's actions have led to Bob Sheldon's death. This weighs heavily on Johnny, and he feels guilty and ashamed. He knows he can't go back to his old life and this contributes to his sense of despair.
* When he's in hiding: While hiding from the police, Johnny is constantly aware of his situation and the trouble he's caused. This fuels his sense of humiliation and isolation. He feels like a failure and a burden to his friends.
It's important to remember that Johnny's humiliation stems from a combination of factors:
* His social status: As a Greaser, he's constantly put down and looked down upon by the Socs. This fuels his sense of inferiority and self-worthlessness.
* His violent actions: Johnny's act of killing Bob, even in self-defense, weighs heavily on his conscience. He feels responsible for the death and this adds to his sense of guilt and shame.
* His isolation: Johnny's fear of the police and his desire to protect his friends contributes to his isolation. He feels alone and trapped, which further amplifies his feelings of humiliation.
Ultimately, Johnny's humiliation drives him to act in ways that are ultimately self-destructive, but also deeply human. He acts out of desperation and a need to find some semblance of self-respect.