Another DNF. I feel sad about not finishing because I really, really wanted to have a meaningful conversation with this book, but I just can't. 
 The people who don't like this book tend to all have the same gripe: the worldbuilding. It maketh no sense. I agree with that, based on what I read (about 22%, according to the read-o-meter on the status updates). But here's why I'm sad: there were kernels of good ideas in here. 
 Take the idea that emotions are caused by chemicals in the brain. It's not something Oliver made up, of course, but clearly she's aware that science has discovered many of the compounds responsible for "love" and other emotions. The idea itself is just a little bit spooky. Few of us (I'm kind of an exception) like thinking of ourselves as elaborate Meat Robots, animated by electro-chemical reactions. A lot of questions naturally arise: if emotions are chemical in origin, can they be artificially manipulated? Could a despotic government have an interest in controlling people by muting their emotions? What would a society be like where the adults have no emotions? What are emotions FOR, in the evolutionary scheme of things? If science is ever able to fully analyze the chemistry responsible for "love", is that the end of love poetry? There's a lot of potential there, and a lot of different paths to follow. 
 But see, here's the thing: Oliver doesn't seem interested in digging into the existing science or "emotions" as such. She only seems interested in love. And, OK, I'll allow that love is interesting, but it's also not a simple thing. Oxytocin is one chemical implicated in love; it's probably not the only one, but I don't think you're going to effectively get rid of love without it. However, it is also responsible for a whole other mess of stuff. It's involved in childbirth, orgasm, breastfeeding, parent-child bonding, anxiety, empathy. Studies have shown it might help alleviate the symptoms of autism -- if it were eliminated from people's brains, would everyone act more autistic? It facilitates feelings of trust and empathy -- can you even HAVE a society without those? 
 Oxytocin is implicated in memory, friends. My own anecdata backs that up -- don't you find that you remember an event much more clearly if you had a strong feeling of some kind during it? You remember facts better if you care about them. That, in my unprofessional opinion, is what emotions are FOR. 
 I love speculative fiction involving neurology. I want to explore those kinds of questions. I LIKE the idea of love as a disease, believe it or not, but Oliver does not appear interested in the questions or their answers. She's trying to fabricate a Forbidden Love scenario. Which, OK, plenty of people find interesting. Just not me.