What are some ways to show Jeremy grew as a person throughout the book?

When Jeremy is introduced, he is an orphan who feels distant from the world and longs for parental figures to look up to. Once he becomes an adult, he marries Jenny Tremaine and adopts her parents as his own. Now feeling like he belongs to a family, Jeremy begins to learn more about the relationship between June and Bernard Tremaine and learns more about himself in the process.
Prior to getting married, Jeremy remained disconnected from the world. As a teenager, he was only comfortable with playing with his friend Sally. After dropping out of the University of Oxford, his lifestyle consists of a lack of commitment to relationships, jobs, and living spaces.
After being married, Jeremy visits the site of his in-laws' honeymoon. There he notices a boy being abused by his father and assaults the father. This act of violence showcases Jeremy's willingness to help those who are not in his family.
Another interesting thing to note is how Jeremy develops his own worldview. As he learns more about his in-laws, he is very critical about their philosophical perspectives and decides to develop his own, which is based on loving those who are alienated.