It actually is a pretty reasonable expectation for someone not completely clueless about education. Many people in fields like mathematics or CS (and sadly also in the respective teaching positions) have only very rudementary concepts of the inner workings of the human mind, and e.g. equate the content with the mode of delivery.

> to someone of moderate learning/intelligence.

It's mostly about the learning, not the intelligence, i.e. current state of research shows only loose correlation to intelligence (g factor) and favors models that use a domain-specific skill to explain maths competency. Intelligence will certainly help, but its effect is quite overvalued.