I don't like Westerns except for ones like True Grit

Saw True Grit on New Year's Eve.  Read a number of reviews including one by Stanley Fish at the New York Times.  Never saw the John Wayne version of 1969 nor read Charles Portis' book.  That said, I liked the attempt at realism.  The language captivated me.  It was formal and with surprising word choices and vocabulary not typical of Westerns.  Yet the characters seemed to disclose themselves and their feelings more deeply.  Perhaps normal, everyday people back then were like that.  I've read a few letters from that time from ordinary people which seem to bear that out.  (Think I may take up some reading from authors of that period, the late 19th century.)  The most interesting character was Mattie, the fourteen year old whose determination to seek justice for her Father's killer created the story.  While many justifiably are fascinated by the role of Grace in the movie, what I keep pondering is the role of belief, certainty, and order.  What provided Mattie with the self-confidence to pursue her goal?  She is single minded and optimistic that she can accomplish it.  Why did she so doggedly desire to do so?  Realistically, her talents should have been directed to taking care of her family rather than endangering herself in such a manner.  Why did she have such Faith?  It seems clear to me that she had a view of the way life is supposed to be.  There is an order to existence that calls not only for proper spelling, something very important to her and I'm led to believe a key to her character,  but capture and punishment for the criminal who killed her Father.  Despite all the danger she has something in her to keep her on the path to this result she deems necessary.  A reasonable and rational person in the normal sense of those terms would have weighed the costs and demurred.