Before I Go to Sleep by S. J. Watson

As I sleep, my mind will erase everything I did today. I will wake up tomorrow as I did this morning. Thinking I'm still a child. Thinking I have a whole lifetime of choice ahead of me...' Memories define us. So what if you lost yours every time you went to sleep? Your name, your identity, your past, even the people you love - all forgotten overnight. And the one person you trust may only be telling you half the story. Welcome to Christine's life.