Either I am the most stupid mf in existence, or... well.
Anyways, I kinda need more than a quick hint.
I feel like you need to advertise the puzzle someway ingame. As
1. No puzzle like it has appeared previously
2. Numbers would prolly be on peoples mind with the code thingys you can find (that I still don't know the purpose of)
3. I wouldn't imagine most people actually reads the books nor much else that had long text (I do because I like that sort of thing. But not many do. And even I get sloppy sometimes)
But I might just be dumb too. That is always a possibility.