This resonates strongly with me. I've written before about my surprise that many programmers working today really have no idea at all how a computer actually works, and yet they can still write good software. Lots of people know how to drive a car, but they haven't a clue what actually happens when they press on the gas pedal, or the brake, or turn the steering wheel.
I've noted that it is quite powerful, sometimes, to actually understand how something works. Martin makes this point better than I have:
If you simply remember how to do something, then all you can do is use it the same way over and over, but if you understand how it works, you can reason about it. Once you can reason about something in your mind you can contemplate why it is the way it is, you can apply your entire creative mind to making the most of it, and you can implement and question improvement – you own it intellectually.What he said.