Can anyone know what they don't know?

We say that someone does not know what they don't know. There are lots of people who act as though they know everything and do not have anything more to learn. Well, none of us know what we don't know. The critical characteristic is to recognize that there is more that we do not know than we do, and that there is no shame in it. In fact, the shame is in not recognizing this. An eagerness to question what we know and to learn more is part of being a mature adult of any age. As I grow older, I am humbled by the immensity of what I still have to learn.