As a kid I thought I was simply a slightly fast reader until I happened to take a copy of https://www.amazon.com/Clan-Cave-Bear-Jean-Auel/dp/060961097... to a bath. I started, got caught up with the story, finished it, and finished my bath. My mother was so astounded that she quizzed me to verify I had actually read the book, and then estimated how what my reading speed had to be.

The weirdest thing is that my brain really does play catchup. I told my mother to test me by picking random spots and reading a few sentences. I was then able to tell her what was going on, and when handed the book could find the passage. That I was able to do. But the book was still jumbled up in my brain - I couldn't have given a plot summary for a day or so.

I strongly suspect that this kind of "brain pipelining" with large amounts of buffering is critical for really fast reading. Get every slow step out of the loop, only do what's fast. Let the slow bits of your brain catch up.