I had a very similar story, except I didn’t receive positive reinforcement in the form of quarters from my moms.
Instead, I received negative reinforcement by punishment and elimination of distractions(tv, friend visits, outings, video games, etc) because I misbehaved quite a bit as a child. As a punishment, my parents created an environment where the only interesting, entertaining thing to do was read books.
When I finished all the fiction I we had, they put their old college txt books in front of me. I swear to god I was reading
Macroeconomics 6th edition and
Introduction to Logic 2nd edition in 4th grade. Soaked it up like a sponge too.
So very similar to you
@ignorethis , I was reading at a "12th grade lvl" in 3rd grade. Weird method by my parents to get there, but it still worked. I say this to say that parents can have an incredible amount of control on child reading outcomes.