That seems to be the only thing that makes sense, but does the text say that anywhere?
It does not. It doesn't quite not say it, either:
1) At 15, Voldemort creates his first Horcrux from Abagail Myrtle.
2) After he "grasp[s] the stupidity of ordinary people", Voldemort decides to invent a better ritual.
3) He spends "years" refining it in his imagination.
4) Quirrel finds one of the Horcruxes which Voldemort had hidden in the "hopeless idiocy of [his] youth"
So, is "when he grasped the stupidity of ordinary people" + "years" < "youth"? It seems unlikely. But I do not think that it is quite ruled out.
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 112.
There is 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.)
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: