Before I Go to Sleep by S.J. Watson

Due to a mysterious accident, Christine wakes up each morning not knowing who she is. Her husband, Ben, has to explain who she is and who he is. She goes through the day and then forgets it all by the time she wakes up the next day. But then she starts remembering things and writing notes down in a journal so that she can remind herself who she is. She starts to suspect that her husband is telling her lies. How do you get to the bottom of your life when you can't remember yesterday?

A super-thriller that kept me glued.