The Hero's Journey

The Hobbit is probably the best example of The Hero's Journey you could ever find. It immediately starts off with the depiction of Bilbo and his calm, peaceful life. He's comfortable with his comfy life living in Hobbiton, but then Gandalf shows up and literally calls him on an adventure. When Bilbo finally came around and decided that he wanted to get away from his peaceful life, he crossed the threshold and went on a magical journey. The trials of Bilbo's journey with the dwarves and Gandalf include getting trapped by trolls, goblins, wargs and narrowly escaping them all. The troop of dwarves, Bilbo and Gandalf were helped by the eagles when they were being attacked by the goblins and wargs. Then, of course, there was that little brush with the dragon that they had but naturally the good guys had to win that battle. The transformation happens when Bilbo sort of betrays the dwarves and gives the Arkenstone to the elves but he actually did it with good intentions. The ultimate boon, for Bilbo at least, would be that the adventure was finally over and he was able to go back home safely. He was happy that he had chosen to go on this trip and have that experience but at the same time, he knew something had changed inside of him and that he was never going to be the same as he once was. When Bilbo returned home, he had lost the friendship and respect of his fellow hobbits, however, he didn't really care. He had the friendship of Gandalf, the dwarves, and the elves and that was just fine for him. The return home was filled with reminiscent memories and ended with a very humble hobbit returning the comfort of his cozy hobbit hole. 

The only things that were really out of place in comparison of the Hobbit and the Hero's Journey were the aid of something supernatural and the refusal of the hero returning home. The supernatural aid in the Hobbit would be the ring that Bilbo found and unknowingly took from Gollum. In a typical cycle of the Hero's Journey, the supernatural factor tends to happen before the threshold is crossed and in the Hobbit, it happened after the fact. Bilbo also showed no signs of reluctancy to go home. In fact, he was excited to return back to his tame, adventure-less lifestyle.