Hard work pays off.

Even heroes have flaws.

The desire for revenge can be destructive.

Breaking the rules is sometimes necessary.

Tough situations can be turned into triumphs.

One’s fate is inevitable; it cannot be avoided or changed.

Percy cares more about his mother than his friends.

Completing a quest is important to Annabeth.

Everyone desires acceptance.

Half-bloods have complicated relationships with their immortal parent.

The right thing and the easy thing are rarely the same thing.

Grover’s friendship with Percy grows stronger throughout the novel.

The Greek gods are the source of Western civilization.

Collecting memories is more important than collecting things.

Most journeys lead back home.

Growing up, or coming of age, is not easy.

Percy cannot complete his quest without his friends by his side.

Challenges strengthen one’s character.

It is never too late to change your ways.