The Hobbit by J R R Tolkien

The central theme is the transformation of Bilbo Baggins, a comfortable and predictable hobbit, into an adventurer. This is highlighted early on: "This is a story of how a Baggins had an adventure, and found himself doing and saying things altogether unexpected." Bilbo's initial aversion to adventure ("Nasty disturbing uncomfortable things! Make you late for dinner!") contrasts with the "Tookish" side that awakens within him, driving him to participate in the quest.