We are not well adapted to focus and filter information. For the majority of human history, the information available was virtually all relevant.
But now, we have an overload of information. Our first reaction is to believe we need to know it all to succeed... But we immediately run into a problem: there's vastly more than we can ever handle. So we resort to silly brain tricks to convince ourselves and others that we either know it all, or that most information isn't important.
We can do better.