I know that "character loses their memory when it's convenient for the story" is an annoying trope, but I gotta make the mystery last a bit longer for Cyrus here. Of course, the audience is free to remember everything that transpired in the secret study ;)
In other news... chapter title drop! I went back and checked how many times this has happened in the story - it's something I try to fit in when I can - and here's what I came up with:
Chapter 2 - Said three times, as a motif for the chapter (Rule of Thirds)
Chapter 4 - on page 6
Chapter 5 - on page 11
Chapter 8 - on page 19