Final answer:
Peter means that Wendy is more important to him than anyone else. He is interested in Wendy because they have a deep connection and share adventures together.
Step-by-step explanation:
In the story, when Wendy gets angry with Peter, he says, "One girl is worth more than 20 boys." By this statement, Peter means that Wendy is more important to him than anyone else. He values her presence and companionship, believing that having just one good friend like Wendy outweighs having many acquaintances. Peter is interested in Wendy because she understands him and shares adventures with him. They have a deep connection, and Peter cherishes their friendship.