'Fault in Our Stars' Author: I Cried When I Saw Shailene Woodley On Set (Video)

John Green tells THR he was skeptical Hollywood could get his novel right, but "knew the movie was going to be good" as soon as he saw its stars in character.

Author John Green may be Hollywood's new It boy of YA literature, but the Fault in Our Stars author was hesitant to let the studios get ahold of his book.

He forbade his agents from sending out advance copies to producers, and says it wasn't until he was on the set of the adaptation, toplined by Shailene Woodley, that he knew everything would be all right.

"The first day of filming I was so nervous. I had no idea what to expect," he tells The Hollywood Reporter. "When I saw Shae and Sam Trammell and Laura Dern, I just started crying. I knew the movie was going to be good."

STORY: 'Fault in Our Stars' Author John Green's Multimedia Empire

Green unreservedly offered his opinions on Hollywood during a photoshoot for the May 9 issue of The Hollywood Reporter magazine. 

"I think Hollywood can at times underestimate the complexity and intelligence and intellectual curiosity of American teenagers," Green says. "Particularly when imagining audiences they sometimes fail to credit teens in flyover country with the intellectual sophistication and curiosity they actually have. I wish I saw more movies that did a good job of that. There are some, which is great, but I wish there were more."

Read THR's revealing profile of the author here.