The world we live in today is vastly different than the world our minds, and behaviors, evolved for. Humans originally developed their unique traits about 1.8 million years ago and the greatest achievement then was the formation of village-like societies. Nothing changed until about only 40,000 years ago, where still, the greatest accomplishment was seasonal trade between tribes. But at a mere 10,000 years ago, humans formed large scale civilizations and our societies had grown massively from that point to this very day. Because genetic evolution moves so slowly, it cannot create adaptive behaviors to keep up with a radically changing world. It is very unlikely that human behaviors adapted to the last 10,000 years; without a doubt, they aren’t adapted to the radical societal changes of the last 150 years.
So we’re left in a modern world of today with a brain built for a world 10,000 years ago. Obviously, we see quirks. We see irrational behavior because the mechanisms in the head were built for an entirely different environment.