THE ONES WE DON'T KNOW WE DON'T KNOW (Biographical)

I've always been impressed by the sayings of former Secretary of Defense Donald Rumsfiled, particularly

From Department of Defense news briefing, February 12, 2002.

• Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns -- the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones.

I've frequently puzzled over the meaning of "the ones we don't know we don't know." But just this past week, I have twice experienced the truth of this statement. A few nights ago we were invited to a dinner at a home I had been to several times before in a large subdivision with a complex layout but hadn't been to the home in some time. Naturally having been there several times, I thought I remembered how to get there, but, after wandering around the subdivision for quite awhile, we decided to go to the club house, that we had seen, and ask directions. So I didn't know that I didn't know how to find the home. Again just today, we were going after church with a group, but separately, to a restaurant that I had passed many times; however, I turned right rather than left at an important intersection. After driving some distance going the wrong way, I turned back the way we had come, and, after going some distance passed the intersection where we made the wrong turn, we came upon the restaurant we were looking for. Once again I didn't know that I didn't know how to find the restaurant.

As Rumsfeld says, ...it is the latter category [unknown unknowns] that tend to be the difficult ones.