1. TFIOS line "I fell in love the way you fall asleep: slowly, and then all at once" was inspired by Hemingway.
2. John Green originally had a cameo in The Fault in Our Stars, but the scene was later cut.
3. John Green's favorite TFIOS movie scene come to life was the cancer support group.
4. There's a meaning behind Hazel's name.
"Hazel is an in-between color, and she's in between a lot of things: In between healthy and sick, in between adulthood and childhood, in between breathing air and breathing water, etc. So that seemed like a small way of communicating the instability and fear (but also excitement) of that time of life."
5. And the same goes with Augustus Waters.
6. Hazel watches America's Next Top Model because John Green wanted to show that despite her illness, she is still a teen.
7. The Fault in Our Stars was inspired by a girl named Ester Earl, but the character of Hazel was mainly imagined by John Green.
8. An Imperial Affliction was created to mirror the story in TFIOS.
BONUS: Paramount bought the movie rights for Looking for Alaska, but it's unlikely we'll ever see it on the big screen.
Responses have been condensed and edited for clarification purposes.