When I was a kid I really liked Roald Dahl's books.  Charlie and the Chocolate Factory, Fantastic Mr. Fox, and Danny, the Champion of the World.  I was even interviewed on the radio about his life and writing.  My favorites were two of his short stories:

The Wonderful Story of Henry Sugar from the book of the same name tells the story of Henry, a gambler and layabout who wants to cheat at cards.  He meditates on playing cards until he is able to identify a card from the back.  It takes him three years to hone this skill and after he succeeds, he is no longer interested in making money for himself.  His self-disciplined practice changed him so much he chooses a heroic path instead.

The Hitchhiker from the same book was about a driver who picks up a master pickpocket who is so adept at his trade he calls himself a fingersmith.  The two are pulled over by an unpleasant police officer who threatens the driver with fines and jail time.  After they drive on, the fingersmith reveals a happy secret.

These two stories about mastery and changing for the better through a spiritual practice still resonate with me.  Living the Hero's Journey is all about following a path of mastery and becoming more than you are, and these ripping yarns illustrate these ideas beautifully.  Highly recommended reading.  (Although you may want to give The Swan from the same collection a pass.  It's pretty tragic.)