Gabrielle Zevin wrote ELSEWHERE, which was on summer reading two years ago. She follows it up with this story of a girl who comes out of a coma after hitting her head to find that she remembers nothing of the last two years. I was surprised at how serious this book was. It is an interesting look at a girl who is given the opportunity to have a do-over and choose to make changes in relationships and situations that normally people would feel that they had no choice but to continue on with.
I like books about starting over. I don't know any other amnesia books, but HOW NOT TO BE POPULAR by Jennifer Ziegler is about a girl who is constantly moving to new towns because her parents are constantly starting over. She decides not to even try to make friends in her new home because she is tired of having to leave them behind.
KEEPING THE MOON is about a girl who leaves her demanding mother to go live with her laid back aunt and finds that other people's opinions of her don't really matter.