Societies in which we grew up had certain rules that evolved for the smooth functioning of groups of people living together. Human sacrifice during the time of the Aztecs and Mayans was thought to be a good way to conduct their societies’ rituals. At the time, everyone thought it was a great idea. It was the best thing a person could do to repay the gods, whom the believed had also sacrificed their lives to keep the Universe running.
Of course, we see this as completely absurd now, as did the Spanish conquerers of the Aztecs. The Spanish had their own absurd practices, which they imposed on the the Aztecs, but they were the ones who prevailed on the Aztecs to stop killing people to appease the gods.
As children, we are taught rules and beliefs of the society we were born into. If we want to be loved and accepted, we conform to them. Then, when we grow up, we mindlessly pursue those values, unless we are part of the few who question them. But usually, people just go along with them. They will be accepted and even rewarded, while those who buck the system will be considered outsiders.
Being alone and friendless in the world is a very unhappy state. So we fit into whatever mould our society presents. If it is a materialistic society, we will be a success if we amass lots of money and possessions. If it is a society that values sharing the wealth, we will be unselfish and giving. If it is a society that values spirituality, as in Tibet, the highest attainment is uniting with Divine Consciousness.
Society is just made up of lots of people who go along with the program. The problem is when a society aggressively imposes its belief system on others. It punishes people, imprisons them, or kills them. So that is why so many just fit into it. It is easier not to question the values and just try to get by on a daily basis.