what is the theme around parent child relationships in this story

Percy has struggled with the idea of family since birth. Having never known his father, the only parental figure in his life was his mother, whom he loved very much—however, this made it harder for him to watch her get abused by Gabe, a man who was supposed to be a father figure in his life. At the end of the story, Percy meets his real father. He does not feel a familial connection to him, but he does feel happy at the idea that his father is proud of him. Percy learns at the close of the novel that family can extend beyond blood ties, when he feels strong kinship with many of the other half bloods and people who have helped him along his quest.