Of all the people who might have a going interest in the meaning of life, teens in love are among the most likely. Add in terminal cancer, and you get The Fault in Our Stars, a young adult novel and movie that's nominally about relationships and romance, but secretly an ode to amateur philosophy.
This pairing of plot devices makes intuitive sense: Dying people face the unknown, forced to try and feel okay about the lives they've lived; and teens face endless days trapped inside their own heads, feeling all the feelings, trying to make sense of their hormone-riddled worlds.
The two main characters, cancer-ridden teen lovers Hazel Lancaster and Augustus Waters, spend a lot of time talking in vaguely cosmological language. "Even if we survive the collapse of our sun, we will not survive forever," Hazel says in her first act of flirting with Gus. "There was time before organisms experienced consciousness, and there will be time after. And if the inevitability of human oblivion worries you, I encourage you to ignore it. God knows that’s what everyone else does.”
It's meant to be wry, but also earnest. This is the perfect pickup line for a bookish 17-year-old: It's winningly bleak and smart-sounding, but it's also grand. She cuts right through the metaphysical noise: Every interaction, even oblique flirtation with a boy, is framed against the inevitable end of human existence.
Hazel can probably pull this off better than most people—after all, she almost died for the first time when she was barely a teenager. But she can also do it because she's 16, an age when every new experience feels significant. In declaring the futility of human life, she's indulging her own attraction to grand narratives while cockily challenging the worth of emotions. It's a ploy to cauterize her own feelings, which are definitely there; we see them in full color in the grand love story that unfolds during the rest of the book and film.
Other parts of the dialogue have a tinny philosophical echo, too: talk of the size of infinity, with the conclusion that "some infinities are bigger than other infinities"; more statements of human futility, like the certainty that “we’re as likely to hurt the universe as we are to help it, and we’re not likely to do either"; and, of course, the title, which is a Shakespeare reference, but also a strong statement of cosmology.
It's not quite right to call this dialogue generic. It is, but it also captures the way a lot of people probably think about the nature of the universe: In vaguely grandiose terms, full of beautiful metaphors about mysteries like the stars. Because they're teenagers, and because they're dying, the philosophy-tinged conversations between Hazel and Gus have more urgency: They're trying to figure out this life thing in a way that fits their matching taste for irony and equally strong intensity about being young and in love.
This need for grand purpose and meaning, for pithy statements that explain the human condition—it's a human need, and a spiritual one at that. It's just that when you're dying, and especially when you're 16, you can cut through the slog of life a little bit more easily, letting yourself see every moment through faith in emotional grandeur.