Once you learn about Bayesian Reasoning, you understand why humans are semi-retarded apes. But I’m being too generous.

Eliezer Yudkowsky gives an excellent primer to Bayes’ Theorem: An Intuitive Explanation of Bayesian Reasoning
And the advanced lesson: A Technical Explanation of a Technical Explanation
Remember this: “I usually take the moral that your strength as a rationalist is measured by your ability to be more confused by fiction than by reality. If you are equally good at explaining any story, you have zero knowledge.”

Keeping in spirit, I cannot supply a verbal explanation.