[[WMG: Augustus actually smokes]]
He grabbed the cigarette because it has already become a habit for him. When Hazel dnapped at him, he realized that him smoking would really turn her off he decided to make up this "metaphor".
That also explains why he tried to buy cigarettes at midnight under his health conditions. He claimed it was "just to prove himself", but before Augustus was shown to know how sick he was, declaring that his body was almost all cancer. Considering the fact that he was addicted to nicotine it's makes more sense. I swear, take cigarettes away from a smoker and they will stop at nothing to get some after a short amount of time, because it's a freaking addiction.
[[WMG:Hazel dies shortly after the events of the book.]]
Gus's eulogy was a sort of double ending. It was a clever plot device serves as closure for both of their storylines, as it is the thing that punctuated both of their lives. Since we know what the eulogy says and how Hazel responds to it, we know what happens before and when Hazel dies. Since Hazel is satisfied with her life choices, I get the sense that she's confident about facing her own death.
** [[WordOfGod Practically confirmed by the author]], who said that the letter in the end symbolizes spiritual marriage, and that "comedies end in marriage, tragedies end in death, and [he] wanted to do both."
** Who needs [[WordOfGod the author]]? [[TheHeroDies She took the lift, didn't she?]]
[[WMG:Hazel writes her own FanFic in the ''An Imperial Affliction'' universe.]]
It's a crossover in which the Dutch Tulip Man is actually a secret agent who's been trying to track down a rogue botanist who's developed a deadly new strain of Dutch elm disease, and shortly after Anna's death, he teams up with Staff Sergeant Max Mayhem to bring him to justice.
[[WMG: [[spoiler: Hazel discovers that she's pregnant shortly after the events of the book.]]]]
[[spoiler: When she had sex with Augustus, he knocked her up, and he died before she could find out about it.]]
* Considering Hazel's health, I would be extremely surprised if this were even possible.
** Also, it was stated in the book that they ''did'' use a condom. Of course, there's a chance that it may not have worked, but still.
[[WMG: Nat Wolff will vlog about playing a blind character, and the set in general]]
...with his brother, in the style of a Creator/JohnGreen Vlogbrothers video.
** Jossed. He did a video with John but didn't even take the opportunity to say "Good morning, Alex" instead of "Good morning, Hank".
[[WMG: Hazel is an UnreliableNarrator.]]
She sees herself and Augustus as sophisticated, worldly and [[StealthPun erudite]], while she has huge gaps in her education and you can see through the cracks so to speak that [[spoiler: healthy]] Gus' appearance ranges from [[{{Adorkable}} attractive an an awkwardly adolescent way]] to, when brandishing his unlit cigarette, absolutely ''ridiculous''.
[[WMG: Augustus is the anti-[[Literature/TheCatcherInTheRye Holden Caulfield]].]]
From their background (Holden's midcentury/Silent Generation, East Coast, prep school, hanger-on of the fencing team; Gus is millenial, Upper Midwestern, public school, former basketball star) to their affectations (Caulfield hates "phonies", Hollywood and the word grand, Waters is acutely aware that he is playing the role of Augustus Waters and his first word in the book is "Grand") to their aspirations (Holden wants to stay a kid, Augustus wants to be remembered as a Great Man but [[spoiler: dies while still a boy]]). Heck, even their ''authors'' (Salinger was famously a recluse, Green is a social-media phenomenon).
** Salinger once seriously offered to greenlight a stage adaptation of ''Catcher'' on the condition he play Holden. Green once announced he would be playing Augustus in the ''TFIOS'' movie as an AprilFools prank. ShoutOut ?
** ''"Gus wants to have a big and important and remembered life, and so he acts like he imagines people who have such lives act.'' - Creator/JohnGreen
[[WMG: John's role in TheFilmOfTheBook will be...]]
Lidewij. He'll be dressed in drag during the whole thing. More seriously, he'll be [[spoiler: the priest at Augustus' funeral (since John Green was once a chaplain), or in some other way linked to Gus' death.]]
** It's possible he could be the man who buys the swing set.
** Or he could be just some guy in talking to a camera in the airport scene...
** Or he'll be the one to say "The beautiful couple is beautiful!"
* The Chaplain idea is very nice, but at a serious scene like this, the very last thing the filmmakers would want is something to take the book-loving fans out of the moment and make them go, "Hey! That's John Green!" So unless it was handled very deftly, I think he'll be in a comic sort of role.
** Personally, I'm hoping he'll be a waiter in the restaurant scene, with the worst fake mustache and worst fake Dutch accent in the world.
** Well, never mind. He was going to play the[[GenderFlip father]] of the girl who tried on Hazel's cannula, but the scene got cut.

[[WMG: In-universe, ''The Fault in Our Stars'' was written by Van Houten.]]
Hazel encourages him to sober up and write another book. Having met someone that reminds him so much of [[spoiler:his own daughter]], Van Houten takes what he knows about Hazel and Augustus (from what he learned when he met them in Amsterdam [[spoiler:and when he went to Augustus's funeral, which would explain how he knows about Isaac]]), fills in the gaps with his imagination, and writes [=TFiOS=].
* ...Whoa...
* That would explain a lot of things, but here's a trip-up: why would he depict himself as a colossal jackass to Hazel and Augustus? Would that be his way of redeeming himself by showing the world how he really is, how he treated two of his fans who bothered to come to Amsterdam to see him?
** Let's go with "yes."
* It would be fitting, given John Green being partially inspired for TFIOS by his time as a youth chaplain and his friendship with Esther Earl
* It would also explain why [=TFiOS=] can come off as a bit pretentious or an acquired taste (I love the book, but let's be honest), or why Hazel and Gus are so much more intelligent than the average teens. ''Van Houten'' comes off as a bit pretentious, and it's clear ''An Imperial Affliction'' isn't for everyone, but he also seems self-aware enough to realize it (hence why he had Hazel's dad admit he didn't like ''An Imperial Affliction'' as much as Hazel did), and Hazel and Gus are probably the first teenagers he's met in a long time. He realized they were smarter than average, but when he wrote them, he elevated their intellect to almost adult level, while still making an effort to keep it believable (hence why they misunderstood his comment about infinities).
* He could've found out about certain other details from Lidiwidg. If he made an effort to sober up and write again, she may have been willing to tell him about Gus and Hazel's kiss in the Anne Frank house, etc. She may have even contacted Hazel to ask for other details!
** That would certainly explain how he'd know about the egging incident, the meeting with the girl and her mother, and the existance of Hazel's fellow classmates (including the best friend who had the hots for Augustus.)
** A bit of a FridgeLogic for me: How on earth would he have gotten permission from Hazel and Gus's parents to write a book based on their children? They hardly know anything about him short of him existing, a published author of one book and living in Amsterdam. Gus's parents are, of course, in mourning, and assuming Hazel told her parents how Van Houten acted around her and Gus, why would they ever want to have anything to do with him? It just seems like he's asking for trouble writing about the personal lives of two kids he knew for a day at most.
*** He could've changed the names and just enough of the events that he doesn't get sued.
[[WMG: Van Houten will write a satisfying ending to 'An Imperial Affliction' ]]
* And Hazel will read it just before she dies just so she can tell Augustus the end in the afterlife.
[[WMG: Van Houten was a product of Hazel and August's imagination ]]
* Hazel and Augustus got medical marijuana from Isaac which caused them to hallucinate about the existence of An Imperial Affliction and Van Houten. They went to Amsterdam (marijuana is more or less legal there) their entire discussion with Lidewij and Van Houten was a hallucination. Van Houten was so mean to Hazel because he was a manifestation of the fear she has for her loved ones' well being once she passes away. When Van Houten shows up again, her parents have already told her that they plan on helping others and will be okay after she passes, so Van Houten is much nicer.
** That's not how weed works.

[[WMG:Augustus went to the support group to get a date]]
Gus appears to have dated two girls in his life, both of which he took the first step with and both of which he knew were dying. He's a teenage boy knowing he might die and he wants to get laid before he goes so he goes for targets he thinks will be easy - girls his own age who are also likely to die and therefore might be eager to try sex before they go. Him joking to Hazel that he hopes taking her to Amsterdam will get him laid might not have been a joke after all. It's not like he spent much time at that support group actually supporting Isaac - most of his time was spent staring at Hazel and later trying to get her to go home with him.
* Okay... first of all, he was NEC at the beginning of the story. He had no reason to think he was going to die. Second of all, why would he go to all the trouble of taking Hazel to Amsterdam? He could've very easily wooed her at home. I mean, he's a bit pretentious, yes, but he never came off as a straight-up ''asshole''.
** If Kaitlyn's reaction is anything to go by, Augustus is hot as all get-out and could pick up chicks pretty easily. If he weren't, you know, still mourning for his girlfriend who died of brain cancer.

[[WMG:Augustus wasn't real, and Hazel was in the hospital the whole book, dreaming all the events that supposedly happened]]
Augustus was merely a hallucination caused by a lack of oxygen in Hazel's brain. When the doctors were able to provide her with oxygen, he "died" (i.e. the hallucination went away). This explains why her time with him was so perfect - it was like a dream.