Nick Dunne: All I'm trying to do is being nice to the people who are volunteering to help find Amy.
Sharon Schieber: Nick Dunne. You're probably the most hated man in American right now. Did you kill your wife, Nick?
Tanner Bolt: Whatever they found, I think it's safe to assume that it is very bad.
Officer Jim Gilpin: You ever hear the expression the simplest answer is often the correct one?
Detective Rhonda Boney: Actually, I have never found that to be true.
Amy Dunne: What's the laptop for?
Nick Dunne: Laptopping!
Amy Dunne: I will practice believing my husband loves me, but I could be wrong.
Answer: To my knowledge, the purpose of hitting herself was two-fold. First of all, a facial injury would support the idea that she was abused or in some sort of bad situation. And secondly, to help mildly alter her appearance, so she could blend in more. (Especially considering people were looking for her).
TedStixon