Why does Percy not get to go anywhere special during the summer?

Percy doesn't get to go anywhere special during the summer because he is often stuck at home dealing with family issues and the challenges of being a demigod. His responsibilities and the dangers associated with his identity keep him from enjoying a typical summer vacation. Additionally, his friends are usually busy with their own commitments, leaving him feeling isolated. As a result, he spends much of his summer feeling restless and unfulfilled.