I had the exact opposite interpretation of that line. I thought it meant that Harry still had so little control that if he was trying to get rid of a memory which involved the colour blue (presumably referring to the unicorn and its blood, which was "not white, but pale blue, or appearing so"), he would instead end up removing all such memories without meaning to.
That's rather like saying "he couldn't perform surgery unless he wanted somebody to lose every single organ in their abdomen". Not something you want to use as a tool - at most, it's a very blunt weapon where Harry has access to far better ones for most situations.
The color blue might be a throw away line, except this story has obliviation puzzles. The author needs to give the reader constraints on obvliviation to enable the reader solve the puzzles, which is why I think the line is a Chekhov's gun.
In case it is not clear, the grandparent post quotes oblivation puzzles found in the text from chapters 88-90, e.g. this one from chapter 90:
...“Dumbledore wasn't being very cooperative, and in any case this was several minutes after the critical location within Time
"Harry," the Headmaster whispered, laying his
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 99, 100, and 101. The previous thread is at nearly 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
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