I finally caught up on the reading today. I definitely wasn’t expecting that strange (but fun) little digression - though each of the past stories did spend some time early on setting up the next story in line, so I imagine this will all be very relevant in the final chapters.
And indeed, it’s hard to reason out all of the absurd logic in this book’s time travel mechanics. At first I figured the time travel thing was really just a (melodramatic) vehicle by which the characters got to resolve their emotional struggles, and so we wouldn’t get much information as to how any of it actually worked, because that’s not really what matters in this book. And I still think that, but it seems it will require even more hand waving than I originally thought.
Had the book gone with the bubble universe idea, a few oddities aside, it would be easy to mostly accept the premise. But since the author obviously needed this little “visitor from the future” episode to lay the emotional groundwork for some later event (or so I assume), he clearly felt he needed to provide some additional explanation. And I kind of wish this hadn’t happened. Because before this section, I felt okay giving a free pass that this wasn’t really a time travel book and so no explanation of the time travel mechanics was actually necessary. But now we that got some level of explanation, I feel more like the author put enough effort into working out the mechanics to weave in the things he really needed to happen, but not quite enough effort to actually put the whole thing into a coherent framework.
And that’s okay. Most time travel stories require a fair degree of hand waving, and this book’s character development along with its general theme of “don’t dwell on how past mistakes have lead to present regrets; reflect on the past in order to change the future” are strong enough that I don’t care that much about the actual time travel logic. But nonetheless I’m just ever so slightly more ruffled about it than I was during the first two stories where I basically paid it no mind at all.