Perspective on knowledge: Deep learning and ignorance

"Yes, we don't know how an AI builds its model, but neither do I know how I catch a ball." This was Tim O'Reilly's tweeted response to an article of mine (https://goo.gl/5vqNfg) It's a good point –O'Reilly is the founder of O'Reilly Media and is an exceptionally smart person--both in general and when considering Deep Learning. Knowledge is always the surface of a deep pool of ignorance. This is for at least two reasons.