In a lot of ways Augustus performs his own existence. This is why there are two versions of his character within the novel. The first version we meet is the façade called Augustus Waters. Named, quite grandiosely, after the first Roman emperor, Augustus plays a strong, confident, funny, and charming boy. He continuously fetishizes his own grandiosity. He is convinced that the importance of life is being heroic, leaving a noble legacy, monumentally impacting humanity. This version of Augustus fumbles over calculated monologues in the park. He over-plans Dutch themed picnics, down to the last excruciating detail, purely for stage like effect. He is deluded by showy metaphors of his own construction, like when he sacrifices himself in a video game by jumping on a grenade in order to save children.

As his cancer returns, however, all of this performance falls away. What remains is Gus, a teenage boy in Indianapolis who used to be a star athlete and now finds himself dying from cancer. Gus is the boy his parents have always seen. In fact, Hazel only learns his nickname is “Gus” because it's what his parents call him. But Hazel doesn't love him any less for being Gus. Quite the contrary: She starts calling him Gus rather than Augustus only after they're intimately familiar with one another, once Hazel knows all aspects of him and not just the performed version she first meets. She sees that, underneath the romantic gestures and theatrical grandiosity, Gus is a sweet, caring, and understandably terrified seventeen-year-old guy. What more, it’s his love for Hazel Grace that teaches Augustus its okay to be Gus. As he deteriorates physically, he's forced to confront the fact that he'll die without doing anything humanity at large views as extraordinary, and a deeper spiritual transition takes place. Because of Hazel, he comes to realize that failing to do something extraordinary does not equal being insignificant.

Over the course of the novel the true Gus reveals himself through the most emblematic gesture of his Augustinian counterpart: the act of placing a cigarette in his mouth. The cigarette metaphor serves as a link that binds the two disparate identities. That's because the cigarette reveals the opposite of what it is meant to project: Augustus wants for the cigarette to represent his control over the thing that could kill him, but really it is a device he relies on when feeling most vulnerable, most like Gus. He grabs for the cigarette at times of uncertainty, like when he first meets Hazel or on board the plane, when he fearful of flying.