That's pretty out of context. Before that, they say this:

> The rules aren't complex. The constructs aren't complex.

So yes, once you understand it, you understand it, but they also specifically said it's not hard to get to the point of understanding it. If we're going to assume that any out-of-context quote is equivalent to the entirety of the content, I'll just cite you on this one:

> it’s not a problem

Think of chess.

Its pretty easy to learn the rules. Once you've done that you can watch a game and know roughly what is happening. But its still a hard game to master.