I just wanted to give a quick plug to S.J. Watson's "Before I go to sleep". The main protagonist has a rare form of amnesia, she remembers nothing from the past 20 years and is retold every day by her husband her life story. The reader is quick to become suspicious of the husband and the real mystery starts when Christine accesses her journal which begins - Do not trust your husband.
It feels like the movie "50 First Dates" but it's a book which makes it 10 times better.