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.
Peter Van Houten: In a novel that is somewhat structured around metafiction, with An Imperial Affliction playing a starring role in the fiction we're reading, Van Houten is its keenest representative. As such, he reveals the magical power of fiction while simultaneously demystifying the romance attributed to authorship. For most of the novel Hazel considers Van Houten a veritable god, or at the very least, a powerful prophet. An Imperial Affliction is Hazel’s personal bible. The novel speaks to her about terminal illness in ways that no other medium, or person, or support group ever do. The act of reading Van Houten’s novel is so incredibly personal to Hazel that she mistakenly conflates the novel’s magic with its author’s greatness. However, when Hazel first meets Van Houten, the magic feeling becomes deflated. She sees him for the sloppy and often mean-spirited drunk he really is. She learns that an author is nothing more than a human being, with human qualities and problems.
Van Houten wears a lot of masks throughout the novel. One of his most crucial roles is to depict the variety of ways in which people deal with pain. When we learn that An Imperial Affliction is really a fictional account of the life of Van Houten’s daughter, Anna, who died from cancer at a young age, we are able to see the author more sympathetically. He is the real life tragic version of the fictional Anna’s mother in his novel. It makes him the living embodiment of Hazel’s greatest fear: that her parents will be so distraught by her death that they will not be able to go on.