Warning: I have a lot to say about 
The Sudden Appearance of Hope, by Claire North. I have no idea if it will make any sense.


Let's
 start with the first thing that struck me about the book: it's unusual 
in that it has two hooks.  The premise--the gimmick--is that the main 
character is someone who cannot be remembered.  For as long as you're 
talking to her, she exists in your mind, but as soon as you leave her 
presence for even a short time--a minute is all it takes--you cannot 
remember ever having met her or talked to her.  You can be sitting 
together on a bus and talk for hours, but when you get off at the rest 
stop and reboard, you will smile vacantly at her, because you will 
believe you'd never seen her before.  She can give you a giant stuffed 
teddy bear, and by the time you get home with it you will remember 
having bought it, or won it, or found it.  You can watch a video of 
yourself talking to her and have no memory of the conversation.
So this is the hook--this is what makes the book sound intriguing.
But
 then this protagonist--Hope Arden--finds herself at a party hosted by a
 company called Perfection.  Perfection is a lifestyle app, gathering 
your data and giving you suggestions and instructions, and points for 
following them.  Find the perfect personal trainer; are you sure you 
want to eat that? Here's the haircut that would look best on you; those 
shoes are gorgeous--achievement unlocked! Hope watches Perfection wreak 
havoc on a new "friend" of hers, and is drawn into what I would describe
 as a battle of wills between herself and this product.
So,
 early on in my reading, I felt like this was an author trying to write 
two books at once, about two ideas, and that maybe they didn't fit 
together very well.  But now I think they come together over the course 
of the story.  Not that there aren't obvious ways in which the strive 
for perfection and the notion of being invisible are related. The idea 
of being seen, being deemed worthy, being judged--all of these are a 
part of both sides of the story. 
But there's more to it 
than even that. Hope can never hold a job, can never have friends or 
lovers (though she has conversations and romantic encounters).  She is a
 skilled thief, precisely because not only can no one describe her; no 
one can remember that she was even there.  She is a collector of facts, a
 counter of objects, a reciter of words, because she must always keep 
her mind busy or risk thinking too much about what she is and what she 
isn't, about the things she can never have.
In some ways, this book is in conversation with North's first novel, 
The First Fifteen Lives of Harry August.
 In that book, the main character lives his life to the end and is born 
again, in the same year, to live through the same years again.  He can 
live it differently every time, but he can always remember, as no one 
but one of his kind can, what will happen around him in the world.  It 
is an inescapable, inexplicable biological destiny that can seem like 
freedom or like a curse, but can never be set down (for Harry, even in 
death). 
Harry's problem is the opposite of 
Hope's--Hope cannot ever make a connection with the world; Harry cannot 
unmake those connections, cannot escape what has been and will be.  
They're both situations that can seem despair-worthy, from the right 
point of view, or liberating. Immortality, freedom from consequence. 
What would you give up for those things?
As in 
Harry August,
 the plot is driven by scientific notions that are not just hand-waved 
away, but put into a conspicuous, opaque box with the word SCIENCE 
written on the outside. You don't want to look inside the box--it's a 
shadow theater with no meaning.  There are "treatments" that change 
people, and the main scientist is a neuroscientist who designed an app 
that makes people "better," and also some kind of deep brain stimulation
 thing.  The app basically exists already in a hundred forms, but the 
book paints it as soul-destroying mind control. The treatments are 
treated as an inevitable next step, in a way that doesn't feel that 
organic to me.
But I think I can mostly forgive all the
 Swiss-cheese holes like that because this is a novel of ideas.  It's a 
novel that asks what perfect means (even if no one in the story really 
asks that explicitly), whether gamifying life will remove our  humanity,
 and what it means to live a life entirely without connections. And all 
kinds of corollary questions: when it's impossible for you to live by 
any traditional means, what are the limits of your ethics? What elements
 of interaction go into forming a relationship? (That's one of my 
favorites; I've always thought about how most of your understanding of a
 person exists in your mental image of that person; how does that work 
without a memory?) Is terrorism ever justified?
So I 
can wave my hands with the hand-wavingest among us and take the facts 
presented in this book at face value, and then follow the fascinating 
question of what they mean, what they imply, and what all that says 
about me and about society.  It's been a long time since a book asked 
such interesting questions and let its characters really wrestle with 
the answers.  I want a lot more of these!
(Note: I received this book from Netgalley for review.)