I don't know the origin of this quote, but I relate closely to it: I can drive a car easily (using), but I could not possibly identify the functionality of each part of the engine (understanding).
In order for a technology to become marketable, engineers must respond to multiple iterations of customer feedback. The actual viable product and the ideal tuned design may be constrained by marginal costs or the consumer's abilities.
This is often true for me. I'm not good at planning and reading about a new project before acting. I just need to jump in, screw things up, get frustrated, figure things out, and eventually realize I learned a lot.