Firstly, this book is wonderfully written and is a recommended read. The struggles Leith deals with feel realistic and are heart-wrenching at times to read. This is also true for Zach. They are both affected by Leith's amnesia, but in drastically different ways. I thought the author did a splendid job with this core aspect of the book, handling both of their emotional turmoil and reactions in a believable way. Even Zach's trip-up is understandable and written in a way that makes you sympathize with him. This is also true when it comes to Leith's anger and outbursts. 
 Leith has lost 3 years of his life due to amnesia, but Zach has lost Leith completely. Leith doesn't remember him, and for all things that matter, it is as if the Leith that Zach knew and fell in love with has actually died. Their struggles as they try to get to know one another again were what I really enjoyed reading in this book. I also enjoyed how Zach's thoughts were captured in vlog entries. 
 There are also a few interesting side characters. Leith's brother, Arthur, and Leith's rehabilitation physiologist were anything but flat. They each acted in their own way as pivot-points for Leith's journey of rediscovering who he was, is and wants to become. 
 A few things held this back from being a 5-star read. First, because of the vlog entries, I actually expected them to be used as a plot point later on. This, along a few other plot points, made the book too formulaic. It would have been more enjoyable and unique if the vlog hadn't become a plot device later on (emotional understanding), since it's been done numerous times before. 
 There were also some awkward character-description/info dumps in the first chapter that were unnecessary and could have been mixed into the character building/experiences later on. The reader doesn't need to have a concrete visual of the character from the get-go. For example, Zach's lush lips were mentioned in the first few pages, from Leith's pov, but Leith was still considering himself straight at that point. Not a huge deal, but descriptions like that could have been left for later. 
 Overall, these are minor issues that many readers will probably think I'm silly for bringing up. I recommend this read. It is a great journey of self-rediscovery, rebuilding a relationship, and trying to fit back into a life you don't remember living.