You shouldn't scream at elders.
Andrew is visiting his grandfather and is mad about his grandfather's old-fashioned views.
Andrew wants to tell his grandfather why he's wrong.
Andrew listens to his grandfather's point of view, and explains his own.
Andrew yells at his grandfather that he's ignorant.
Andrew's grandfather realizes that he may be misinformed and thanks Andrew for teaching him something.
Andrew's grandfather is upset and cuts Andrew out of his will.