Discernment

"Nothing you learn here at Oxford will be of the slightest possible use to you later, save only this: that if you work hard and intelligently, you should be able to detect when a man is talking rot. And that is the main, if not the sole, purpose of education."
--Harold Macmillan (prime minister of Great Britain and chancellor of Oxford University from 1960-1986).

Formal learning, life experience, these can help in the development of our personal B.S detector, without question.  Also, at my age it becomes even more clear how needed the Holy Ghost is.