Percy discovers that though Crusty might be a monster, he, too, has faults—in this case, he’s very susceptible to flattery and insults toward his products. That Percy is able to successfully trick Crusty indicates that over the course of his journey, Percy has learned how to identify and then manipulate people’s faults in order to get his way and protect himself. Further, this indicates that Percy’s people skills are perhaps more refined than Annabeth’s or Grover’s—given Annabeth’s tendencies, she might have dealt with this situation in a more physical way.