Why do people so commonly see the investing world so wrongly and become so error prone?

A big part is that our brains didn’t evolve to deal with ever changing landscapes of capital markets. Humans are intuitive thinkers, but markets are inherently counterintuitive. Common sense thinking is important in many aspects of life, but frequently hurts you big with investing. All humans have opinions, but this can be your greatest enemy when trying to time or quantify investing in the markets.