The first is ignorance of which you are mindful, things you know that you don't know. We stay ignorant of some things because it is much easier to look them up when we need the information, rather than carrying the data in our head. Mark Twain's birth and death dates, the approximate population of Larvia, the phone number of your dentist; there are many such. Some are quite complex -- the cause(s) of the Civil War, for example. It is no sin to be ignorant of much of the world's data, as long as one is aware he is ignorant.

The second is a more serious kind of ignorance. This second sort is ignorance of the things that we don't know that we don't know. In this case, we simply have no idea that any data is wanting. Often, we would really be interested in knowing the data, but we don't even notice that it exists at all! It may be said that the process of "discovery" is the process of becoming aware of the unknown data and doing something about it.

We are all ignorant with respect to both classes of ignorance. The process of education is best served by focusing on the second. When we finish our life work of discovery, the real joy of life is terribly diminished. For some people, that happens before they leave adolescence. In others, it never happens.

Be the second kind of person.

I don't know where this came from -- it is an excerpt. I am pretty sure I did not write it, but I wish I had.