He told Vulture of the novel: "I was just possessed! The book is inspiring, fascinating and mind-boggling, and I read it when it first came out and talked about it with my wife and my sons.
"But when I was first approached to direct it, it seemed like a crazy idea - and the book seduced me into it, because it was a puzzle to crack. It's an intellectual book, and you have to make it emotional and visual."
Ang's son Mason has followed his father into the film business, starring as Teddy in The Hangover Part II.
"I just told him, 'Relax! It's a broad comedy. Just enjoy it'," Ang revealed.
"Because that's something we have in common - taking things too seriously. He's trying to make it on his own, and he doesn't want any of my influence, so he's suffering like the rest of them."