The atrocious decay of logic in English spelling is a visible example of how bad things can and will get in a working system. Survival of the fittest kicks in when something gets bad enough, but the fixes stack up like patches on patches. Brain layouts must have as many dead ends, unused areas, redundancies and nonsense as language. City layouts and human appearances are kept at a lower level of decay because they are not symbolic and are comparably more visible. Evolutions many patches left the brain full of many contradictory or opposed system.
Opposed systems lend themselves to control by feedback.
People improve their ability to lie to themselves by not analyzing things like birthdays in a logical manor. The more practice you get, the better you will be able to believe that you like to exchange gifts, you love your girlfriend's dog, and your kid should stay away from sex and study algebra. The importance of the errors that caused WW2 is brushed over while people feel concern for simple things that are too often trivial. Letting yourself believe what is easy and accepted is how so many scientifically minded people can be religious, among other reasons. People who make fools of them selves, but are not fools, put at ease the people around them.