Toby's name change is an obvious place to begin analysis, because it represents a choice that Toby makes which is ironic and contrary to nature. Can one just change one's name? It represents that he does not feel his father's genes deserve to be in his body. He regrets being born to the parents he was born to, and their symbol of authority over him is that they picked his name. So instead of letting them use the word they picked to refer to them, he makes his community call him by a new name, something run-of-the-mill: Jack.
Instead of discovering the identity he discovers, Jack goes on to publish memoirs about his life under the name Tobias, which is literally his father's name. But, in the story, Jack doesn't know that he can simply decide his identity with no one's permission or control. He is living in the constraints of a perception of his mother that is delusional and easy, or else it is accurate and heart-breaking. It is delusional when he thinks she is evil, or that she hates him or something. When he chooses to look more carefully, he finds that the true sorrow of his mother's life is overwhelming to him in deep ways.
Without any analog for these emotional experiences, he ends up drifting through life, constantly perplexed in silence by his own mind. He can fashion ideas in his mind that most people cannot, and he knows enough to get away with his crimes. But, instead, we see a Jack who allows himself to be caught. When caught for stealing gasoline from a farmer, when asked to apologize, we see what this has become for Jack. He thinks pride is the correct emotional response to injustice, but this just leads him to being misperceived. What he needs is simply the attention of the conflict, but it's conflict with his mother that he really craves. He longs to confront her about her terrible, selfish parenting.
