This passage from The Way to Rainy Mountain directly fulfills the role of a myth because (C) it teaches some kind of lesson.
Most myths, especially those that belong to Greek mythology, teach moral lessons. The most common lessons found in these myths are it is impossible to change your fate and do not dare to anger the gods. There are many myths, such as Niobe's and Sisyphus's myths, that explore the idea of the dominion of powerful Gods over humans. On the other hand, the moral lesson that this excerpt from The Way to Rainy Mountain offers is that you have to listen to people that is wiser and older than you.