Common Sense
You know, as Thomas Paine said, common sense is not so common.
The lack of analytical ability on the part of decision makers, and the insistence upon requiring a definitive answer to that which is not, makes one wonder how anything ever gets done.
The obvious answer is that many things must not be critical :-) Although I don't have the cite of the IS bigshot was quoted as saying "A CIO makes thousands of decisions every year, but only four are critical. The trick is knowing which four."
I would say that experience dictates that the trick isn't knowing which four, but rather getting them right anyway.