Why does Willy Wonka pretend not to hear the comments of that children make?

In the book Charlie and the Chocolate Factory and its film adaptations, Willy Wonka pretends to not hear comments to allow them to reveal their personal desires, secrets, or behaviors by responding to something he didn't say. Through this technique, Wonka gains insights into the children's characters without confronting them directly. By feigning inattention, Wonka encourages authenticity and reveals hidden traits crucial to the later events in the story.