I agree that many people chose to become monks "because they were true believers", but I know two facts that show that religious belief was not the only factor

I agree that many people chose to become monks "because they were true believers", but I know two facts that show that religious belief was not the only factor for living in a monastery. First, monks were not the only men to live and work in monasteries. There were many "sub-ranks" (for instance "frère convers" in French, someone that shared most of their life without taking the religious vow) as well as external workers (for centuries, many monasteries had vast domains where monks ruled over peasants, at various degrees). Then, becoming a monk was a social ascension for many. This was still true a few decades ago. My peasant grand-mother had ten children over twenty years, and the only ones who did not stop their studies early, were the three boys who wanted to become priests. The will to study and to change their way of life was a strong incentive. Times changed, and they all found other ways.