I hadn’t seen all of Rosamund’s work. I’d seen four or five things. The Bond movie, Jack Reacher. They always seemed to be two years apart. I was intrigued that, even after seeing four of five movies, I had no sense of her. She was sort-of opaque. In An Education, I even found myself not being aware of what her age was. That was an intriguing thing. Then I met her and she had the most important thing that Amy needed to have, which is that Rosamund was raised as an only child. You just feel it. It’s not that she’s not socialised, but that she’s an orchid. She has that sense. It’s not entitlement, but if you’ve spend your young life being around adults and not other kids, you carry yourself differently. Ben’s thing was that he had lived through this kind of “attention”. You can tell that he has made his peace with it. He has considerable charm. You can tell that’s he’s willing to trade on that. Oftentimes, that can lead to sticky things becoming stickier. And that was key – you have to have that to be Nick. He’s really bright as an actor. He was willing to demean himself."
— David Fincher on casting Gone Girl.