I think the point is that, in a non-healthy brain, the brain can create a balanced and flexible reasoning system that creates inferences that have explanatory p

I think the point is that, in a non-healthy brain, the brain can create a balanced and flexible reasoning system that creates inferences that have explanatory power, but which may not match external reality. Oliver Sacks has a long bibliography of the weird things that can go on in brains. But the bottom line is that introspection is not necessarily reliable.