Green doesn’t underestimate the young adult reader; in fact, he resents that so many writers do. He knows how smart his readers are, and how they’ve been condescended to all their lives, so he writes about intellectual and emotional experiences because he knows they’ll connect with that style of writing. He uses “big words” but knows the reader can discover their meaning either through content or via a Google search. “I'm tired of adults telling teenagers that they aren't smart, that they can't read critically, that they aren't thoughtful…” (Patrick, 2013, para. 11).
If you read any John Green book, you'll most likely cry (he often cries while writing them), you'll be intellectually challenged, and you'll have laid bare almost every human emotion by the story's end.
Here are Green's own words about how he writes:
"The reality of experience is ultimately a lot more interesting to me than what I think is sort of wrongly called "objective reality." Because I don't actually think objective reality is a thing -- certainly not a very interesting thing for fiction, I don't think" (Rosen, 2013, para. 35).
"Yeah, my interest as a writer is not in reflecting actual human speech, which, of course, does not occur in sentences and is totally undiagrammable. That's not my interest. My interest is in trying to reflect the reality of experience -- how we feel when we talk to each other, how we feel when we're engaging with questions that interest us. So, yeah, certainly, teenagers don't sound that way when they talk to us. Like, they don't sound that way *to us*. But they do sound that way to themselves. And that's what interests me. I'm trying to capture that, because I'm not really interested in capturing how they actually sound, because that's not their experience" (Rosen, 2013, paras 33-34).
"Part of the thrill of celebrating that teen intellectualism, where you're reaching keeps exceeding your grasp just a little bit, is in learning, is in getting excited about learning. So there's a lot of examples of that in The Fault in Our Stars: Hazel is wrong about infinite cardinality when she talks about infinite cardinality, when she talks about there being infinite numbers between 0 and 1, and 0 and 2, and Gus frequently misuses big words and stuff. But their intellectual enthusiasm is really appealing to me" (Rosen, 2013, para. 43).