We are being brainwashed by education. By society norms, society expectations. By the law. By current moral teachings, by religion.

We, humans, are getting brainwashed because we cannot retain knowledge beyond a few generations as a collective. We forget what it was like before. 200 years before (industrial revolution), 400 years before (colonialism) , 2000 years before (major religions), 5000 years before (major civilizations), 10000 years before (agriculture), 20000 years before (hunter gatherers), 250k years ago (Sapien hunter gatherers), 2 million years ago (Homo X hunter gatherers).

We forgot why we wear clothes. We forget why age of consent for sex came about to be 16-18. We forgot why we have to go to school. We forgot why we invented marriage. We forgot why we brought in monogamy.

Collective Learning is a distinguishing quality of humans which enables us to transfer knowledge from generation to generation, and advance humanity. But it needs to be better, rather than the details being forgotten every 100 years.