Before civilization humans were more instinctive. Humans were originally more right brained. The ancient world was different than today, because the human ego was more fragile and more conscious of the right brain, while the left brain was less conscious. This is the opposite of today; BC versus AD.
The ancient world by being more right brained, explains why the world view of advanced cultures was often broken down into the specialty gods of mythology, as the controlling factors. These gods were projections of their conscious right brain archetypes or personality firmware, derived from instinct, which controlled the expressions within the less conscious left brain.
If the left brain was more unconscious and less under willful control, one would have had a difficult time, coming to a willful left brain focus; loss of soul. One would need to pray to the god or goddess connected the behavior they wish to do; trigger right brain firmware for farming. The 3-D firmware would output to the left brain and carry the ego along via the output. This was sort of like scaffolding for the ego as it developed; secondary center.
A modern example would be writers block. You sit down to write but you cannot come to a focus to get started. Once the firmware kicks in the ideas flow and you more or less scribe what comes to you. You may even learn something or marvel at your creation. One would be hard pressed to duplicate output this since it did not exactly originate from the ego and left brain. Written language was very important since it offered a way to record such unique output for review.
This brain hierarchy and dynamics; right to left, explains the high level of sophistication, at a time where science was very thin and superstition high. The building techniques of Egypt or Rome, all without modern tools and computers, was connected to right brain data processing. They had the benefits of 3-D neural firmware to do the data crunching; gods would teach them, with the left brain output very sophisticated, once the firmware got rolling.
The right brain is also connected to our instincts and emotions which can also bring the ego a strong sense of focus and drive; fight or flight. Characters like Hercules who was part god and part man would have been someone whose right brain output was more or less continuous to the left brain so he could push the boundaries of human strength; inner animal.
Modern people like to attribute the ancient technical sophistication to aliens and advanced tech, but the human brain has untapped capacities that were more conscious in the ancient world. It make less sense to us since our world view is more 2-D; science and reason.
Going from BC to AD was connected to the ego gradually leaving the sinister right brain and moving to the dexter left brain; arms are cross wired to the brain. The Dark Ages reflected this shift which took centuries to complete. It led to will power, individuality, and age of reason. The future upgrade appears to be a reversal, back, to the right brain, but with the modern ego and left brain more developed as the pendulum shifts.