Why do you think Laurie reported Charles's good behavior grimly, while he had delighted in telling about Charles's bad behavior?

In the
ironic ending to 's short story " " Laurie's mother discovers that although her son
has been faithfully reporting the deeds and misdeeds of a boy named Charles in his kindergarten
class there is in reality no Charles. Laurie is really Charles, which should come as no surprise
to the reader in light of Laurie's behavior at home where he torments his baby sister and often
talks back to his father. Charles is made...