The thing about knowledge is that what you know, you know you know; you know how much you know about what you know; you know what part of it you don't know enough about to say that you know it all.
The thing about ignorance is that what you don't know, you don't know you don't know; you don't know what it is you don't know and have no idea what might exist that you don't even know of, much less know something about.
For the most part, we with conviction live a life of ignorance mistaking it to be one of knowledge. That fact is brought home to us every time we're confronted with evidence of our ignorance, and our ignorance about our ignorance. And then we're not sure we really know all that we thought we knew. All we can then be sure of is that there exists befuddlement.
