One thing I found super super hard to fully grasp and understand in this book is the nature of the disappearances. It's still super difficult to me to understand all the urges they described and the weird transition period where they knew what was disappearing, but not how it worked. This was probably most apparent for me in the end when their bodies start disappearing, and they're just kinda... limping around on 1 leg, despite them being there. It's just so bizarre to be able to see something like that and have no attachment or memory of it, and trying to understand where that barrier was is still super difficult in those more extreme cases.
I did appreciate that they never really went into details of how the disappearances and memory police were really decided though. They're just... a force that's there and we have to deal with it. There's no logic, no order to them or their existence. They just are.
The more I'm thinking of it, the more I'm wondering if this is just a long reflection on memories as a whole. We forget things all the time, and sometimes even visual cues don't actually allow us to remember what something is. Yet we see in both the narrator's story (I forget if she even has a name at this point), and in the real world, that memories seem to be the only things that give anything purpose or meaning in the world. It's our soul, and yet we are naturally in a "cleaning state", with our brains compartmentalizing and moving things all the time. Sometimes we don't forget what things physically are, but alter our perception and memory of what they were. Like the ferry which was now just a house, we alter our past memories to better shape our understanding and they don't line up 100% with reality. Maybe the memory police are just our brains, operating in ways we can't fully understand deciding what's worth remembering and not, destroying those that aren't worth keeping, regardless of whether or not we treasure them. Maybe R is the heart and sentimentality, pushing back "Even date books are important! We mustn't get rid of those!" trying to fight to keep some semblance of attachment we have.
This is probably the best ending I've read in a Japanese author's book so far though, especially compared to how I normally feel with Murakami's work or All She Was Worth. I feel like it ended in a very good spot for once.