Gaslight

For the last week I've been reading in circles. The ebook cover for the next Applied Topology book, A Tapestry of Fire, is ready and all I had to do was give the document a couple of serious proofreading passes before sending it off to the formatting service I use.
Or so I thought.
Instead, I've been going over the manuscript again and again with frustrating and confusing results.
I'm almost ready to go back to proofreading from a printed, dead-tree manuscript! That's how I used to do it, but since getting into indie publishing I've found an easier method -- at least, up to now it was easier. I convert the Word document of a book to PDF and send it to my Kindle via Amazon's automatic conversion program. That program isn't good enough to use for publication -- it gets kind of funky about hyphens, em dashes, and paragraphs -- but it does produce a version of the book which I can read on my Kindle. And it turns out that what I personally need for proofreading isn't necessarily hardcopy; it's something that mimics my reading experience. I read so many books on Kindle that this is quite comfortable for proofreading and minor editing.
The way it usually works, I read the Kindle version of the manuscript and use the Notes feature to highlight typos and wording changes. Then I open the manuscript on my laptop, in Word, and refer to the Notes on the Kindle version to find the places I need to fix. Two or three passes are usually sufficient to give me a nice clean manuscript -- and I'd already reviewed A Tapestry of Fire more than once. So, a piece of cake, right?
Wrong. This particular piece of cake has given me severe indigestion. On one reading, my Kindle decides to show me only the notes for the second half of the book. On another, I discover actual typos which I distinctly remember seeing and correcting at least two revision cycles earlier. I've been going over and over the manuscript and I think it's clean now, but I'm going to look at it again tomorrow. Just in case.
I've been at a loss to explain these sudden problems; or rather, any explanation I come up with is unsatisfactory. Amazon's Notes for the Kindle is suddenly experiencing random failures? Doesn't seem likely. Microsoft Word is sadistically refusing to save random editing changes? I'm almost paranoid enough to believe that one, but not without a motive.
Or -- here's the scary one -- my own brain is shutting down, giving me false memories of having corrected typos I never actually fixed?
That one is so terrifying that I temporarily quit thinking about the problem at all, because I am not ready to go soft in the head. I've got the last book and a half in this series written and I want to finish them, and then I've got a new book ready to go, and... not yet! Please don't let my mind fail yet! Can't it wait until I don't have any more book ideas?
Then, last night, it came to me.
Gaslight.
Of course. Amazon and Microsoft are teaming up to make me think I'm crazy, as part of their secret plan for world domination. And Charles Boyer is probably in on it too.
Paranoia. It's good for solving your problems.