The novel heavily emphasizes the importance of friendship and loyalty. Percy's dedication to saving his friend Grover and protecting Camp Half-Blood showcases the strength of his bonds. He faces numerous challenges and risks his life for his friends, emphasizing that true friendships can overcome even the most daunting obstacles. This theme resonates throughout the story, reminding readers of the value of strong and supportive relationships.

Percy's journey is not only about saving Camp Half-Blood but also about confronting his own fears and insecurities. He encounters terrifying monsters and faces seemingly impossible odds, forcing him to dig deep and discover his inner strength. As he overcomes each challenge, Percy gains a better understanding of his own capabilities and embraces his destiny as a demigod. This theme highlights the importance of self-belief and facing one's fears head-on.

Family, both biological and chosen, plays a crucial role in Percy's journey. Throughout his quest, he grapples with his feelings towards his absent godly father, Poseidon, while simultaneously finding acceptance and support from his friends and fellow demigods. The story emphasizes that family extends beyond blood ties, highlighting the importance of finding belonging and love within a chosen group. This theme adds an emotional layer to the action-packed narrative, reminding readers of the importance of family and belonging.