How is Rowdy's aggressiveness connected to the truth in the explanation Mr. P gives regarding life on the Rez? Accordingly, why have Rowdy and Junior become such good friends?
While initially not connected to one another, Mr. P's explanation to Junior about life on the Rez and Rowdy's aggressiveness can be seen as inextricably linked. When Mr. P sits down and talks to Junior, he explains how his life as a younger teacher was one that sought to remove the unique and distinctive characteristics of Native American children on the Rez. He tells Junior that he "hurt a lot of Indian kids when (he) was a young teacher" and apologizes to Junior, saying that it "was a different time...it was wrong...I was young and stupid and full of ideas." Mr. P goes on to suggest that the Rez is nothing more than a collection ground for the death of dreams. When he recalls how Mary used to be a "bright" and "shining star" that withered over time, it solidifies Mr. P's claim that life on the Rez is one where dreams are blighted and hope extinguished.
Rowdy's aggressiveness can be seen as linked to this condition. Like Junior, Rowdy is a "a big, goofy dreamer." Yet, his condition of life on the Rez is one where dreams are crushed. The fist that meets his face is both a literal fist of his father as well as the Rez seeking to eliminate his dreams. The abuse that Rowdy endures from a father who "drink(s) hard and throw(s) hard punches" is matched with how Rowdy's own dreams are denied and put aside because of life on the Rez. Rowdy finds no outlet for his dreams. Being aggressive is the only realm in which the energy that fuels his dreams can be validated. When Rowdy throws down, he is able to accomplish something that exists in his subjective. This is the closest he gets to accomplishing his dreams. The fact that he is successful in his aggressiveness is the reason why he is that way in the first place. It is one of the few realities that he can envision and accomplish.
One other reality that Rowdy can envision is that his friendship with Junior is something opposite of life on the Rez. While living on the reservation carries blighted hope and ruptured dreams, Rowdy recognizes that his friendship with Junior is almost a sanctuary from such a condition. Rowdy understands that Junior takes him in, shares his dreams, and reminds him of what it means to be a human being. Rowdy is so protective of Junior because of their shared condition of dreaming and wishing for something more than what is. For this reason, Rowdy is filled with anger when Junior leaves the Rez for Reardan.