David Fincher is usually very thorough when choosing actors for his movies. But sometimes everything is decided by chance. According to the director, Ben Affleck got his role in Gone Girl because of his smile! “In the movie, there’s a scene where journalists ask the husband to stand next to a photo of his missing wife, and he does so with a very strained smile. I flipped through Google Images and found about 50 shots of Affleck giving that kind of smile in public situations. So, that’s when I realized he’d be ideal for the part!” Fincher said.