"The first principle is that you must not fool yourself, and you are the easiest person to fool." — Richard Feynman
"The triumph of prejudices over evidence is a wondrous thing to behold." — Paul Krugman
"It takes far less energy to ignore an inconvenient fact than it does to question a cherished belief." — The Greater Fool
We humans are very good when it comes to fooling ourselves. Anyone who has lived through the dot-com and real estate bubbles and the wars in Iraq and Afghanistan needs little convincing of this claim.
Not everyone wants to take the trouble involved in not fooling oneself (especially since there are definite benefits to be gained by being clueless). If you are among the few who suspect this idea might have some merit, welcome to this ship of fools.