This book went from exciting to boring to straight up ridiculous by the end.
The book starts off with the scene where a woman named Alice is about to marry her fiance Seth when she realizes that she doesn't recognize him, even though everybody else doesn't see anything wrong about him. That's surely not an ordinary situation to find yourself in, so the book hooks you on immediately.
Except Alice doesn't actually do anything to figure out what's going on. I don't know, if I ever randomly stopped recognizing someone I know, I would probably make an appointment with every psychiatrist in the city, because this situation doesn't sound even remotely normal. But apparently not for Alice. She acts like she just called off the wedding because she had a little argument with her fiance. She does go to a doctor and gets a brain scan as an afterthought, but mostly she just meets different members of her family and friends for lunches and dinners and has idle conversations with them about how shocked she is, providing us with absolutely necessary details about her friends' personal lives. There are too many characters that don't contribute to the plot at all. There are plotlines that are either hastily wrapped up in the end or aren't resolved at all. For example, Alice's abusive ex makes an appearance and seems to be stalking her, which seems like a big deal for Alice, only for her to tell us in the end that he still keeps showing up from time to time but she's not worried anymore. Why include him in the book at all? Also, there are a few hints throughout the book that Seth might be not as dreamy as Alice paints him, but it proves itself irrelevant.
And don't let me started on that ending. Apparently, the explanation for everything is hypnosis. It just so happened that our main character is extremely susceptible to hypnosis and one of the characters wo has a beef with her conveniently turns out to be extremely skilled in hypnotizing people. I don't think it's actually possible to achieve such an effect with hypnosis, and even if it was, it sounds like something that requires multiple extensive sessions. Considering that our master hypnotist isn't even Alice's friend, just her friend's girlfriend, it seems like she was unlikely to spend enough time with Alice to alter her memories to that extent. So the whole premise is based in something that's highly implausible and probably not even remotely realistic.