Lean not unto thine own understanding

Trust in the Lord with all thine heart; and lean not unto thine own understanding. (Proverbs 3:5-6)
Common sense would thus become uncommon sense. (Big Book)

When I'm upset in any way at all, two things have happened. Firstly, I have concluded something. Secondly, I have concluded I am correct about my conclusion. I have thus leaned unto my own understanding twice: firstly of the situation and secondly of myself. In fact, self-propagated plans and designs are similarly based on two such conclusions, even in a place of apparent complete equanimity.

What I'm supposed to lean unto is God and God's will. This comes in the form of an inspiration, an intuitive thought, or a decision. These cannot be interrogated. One can consult, sure, and review and analyse, but history is littered with examples of things that seemed a great idea to people who were at least superficially well intentioned.

Thus common sense is elevated into uncommon sense: the uncommon sense is also a form of sense, but a higher form and a rarer one.