But the experience was still extreme by any standard.

It still required physical courage and psychological steadiness.

It still placed the miners in an environment where the margin for error was small and where specific competencies — torch management, route knowledge, mineral identification, physical agility in the cave’s varied passages — were not optional but survival-essential.

The fact that the mining was sustained across three thousand years means that the communities who conducted it successfully transmitted those competencies across generations.

Children who grew up in these communities learned, presumably, from the miners who had already gone underground and returned.