David McRaney takes on hindsight bias, i.e. how you " often look back on the things you’ve just learned and assume you knew them or believed them all along":
You are always looking back at the person you used to be, always reconstructing the story of your life to better match the person you are today.
You have needed to keep a tidy mind to navigate the world ever since you lived in jungles and on savannas. Cluttered minds got bogged down, and the bodies they controlled got eaten.
Once you learn from your mistakes, or replace bad info with good, there isn’t much use in retaining the garbage, so you delete it.