Christine wakes up every morning with no recollection of who she is. Sometimes she's a child and other times she's in her early twenties, only to receive a huge shock when she looks in the mirror. Actually, she's in her forties. When she was twenty-six, she suffered an accident--or rather, incident--that caused her to be unable to gain any new memories and for that matter, she's unable to grasp onto most of her memories from before the incident either. Yes, Christine has amnesia. She lives with a man who claims he's her husband, Ben, but she can't remember him at all and then there's Dr. Nash, her doctor, who has been helping her try to regain her memories. He's been having her keep a journal and when she first opens it, written on the very first page, she's told herself not to trust Ben. Throughout Before I Go To Sleep, Christine will try to remember who she is and more importantly, what caused her to forget everything. 
 Admittedly, when I first read the summary of Before I Go To Sleep, it was deceptively simple. It seemed, more or less, like Christine would simply spend the entire novel just trying to remember who she is and what's happened during the time that she's lost. However, it's much more than that. Honestly I can't tell you anymore than that without spoiling it for you; so instead I'll tell you that if you thought it was a bit slow during the first half, it really picks up after that. 
 Can you imagine losing so many memories? Essentially losing a vast amount of time; skipping forward in your life only to find that things aren't what you'd imagine that they'd be? That's Christine's reality. Yes, she keeps a journal--hidden from Ben--and sure, it helps, but regardless, every day she wakes up without remembering who she is. There are pictures around the mirror in the bathroom to help her every morning. Pictures of her and Ben smiling and happy. However, things are different now, after the incident. 
 As the reader, you'll only know as much as Christine does and that's really a key element to Before I Go To Sleep. It keeps you guessing and although I can't say that I was completely surprised by the ending, it did wrap up nicely. Also, I should warn you that should it bother you, there is some nudity and scenes that are sexual in nature in Before I Go To Sleep. Yes, this is an adult book. I can see why the movie rights have been sold for it though--and yes, if they make it into a movie, I'll probably go and watch it because the plot seems like it'd transition nicely into a film. 
 Would I recommend this book? That's a bit difficult to say. Yes, I'd recommend it if you like adult books and the plot has you intrigued. Also, yes, I liked it enough to give it a four; however, it didn't have me flipping pages or staying up late to finish it. Because of that, I don't think that this book is for everyone--or something that I'd tell all my friends to read, unless of course they liked the sound of the plot.