This isn't a very helpful advice. We always understand how it works. Our understanding is often superficial and even wrong but nevertheless sufficient more often than not.
Remembering stuff is what gives you the tools to understand - you simply can't understand without a large collection of facts. Facts aren't sufficient, but they are necessary. Trying to jump over the "knowing stuff" phase leads to a very low quality understanding.
There are, however, some elements of knowledge that are more important than others - and it's often important in learning to check that you actually understand something on which stuff is later being based rather than just forging ahead and hoping it all works out okay.
Besides, the advice was never to just remember. You know? Ask questions, build on your current understanding - if that requires you to go and learn more facts, go do that. It's a question-based method of learning.
Makes sense to me anyway - how I learn most of the stuff I do :/
