Percy Jackson, the protagonist of the story, is a young boy who discovers he is the son of the Greek god Poseidon. Although Percy has been defined as a troubled youth all his life, he desires to learn the truth about his identity and where he fits into the world. Several of his character traits, such as his dyslexia and ADHD, are perceived as problems by the adults around him. As a result, Percy struggles with negative self-image and a desire to prove himself. He loves his mother, who is the most important person in his life, and her disappearance prompts Percy to accept his quest.

Since he never knew his birth father and was neglected by his stepfather, Percy longs for love and acceptance from his friends and family. Throughout the story, Percy is taken advantage of by the gods; they have no qualms about manipulating him to achieve their own ends. This enables him to deepen his empathy for the creatures he comes across, such as Charon and Cerberus. Despite what he has endured, Percy remains steadfastly loyal to his friends and family. During the quest, his relationships with Annabeth and Grover transform into deep friendships.

Percy comes into his identity as both a human and a half-blood. By facing the challenges of the quest, he becomes more empathetic, accepts himself, and gains confidence by converting his “flaws” into assets. He learns that he can overcome challenges in order to help others and feels secure in his relationships with the people who are most important to him.