[mustacheemperor]

What is different between having a new belief and having your brain functionality modified such that you indistinguishably genuinely feel you have a new belief? Wouldn't the act of integrating a new belief also modify your brain functionality somehow? Not trying to start an esoteric argument, I'm interested if there's an actual answer to that.

[kobeya]

You can profoundly understand something because you understand the mechanism of its working and have deeply integrated it into your mental model of the world. Or you can "profoundly understand" something by having your brain remember what it feels like to profoundly understand, and enter that state in association with the new belief. Even if the belief is wrong (and you will never see that it is wrong).