In university, I was notoriously bad at "remembering" things (iow, I was lazy to learn things by heart). I was pretty good at making connections, and I could prove theorems from only knowing a couple of definitions and simpler theorems in advanced math courses. I generally scored average in tests, but I rarely failed (though I occasionally had "original" solutions that teachers commended on even though I failed to reach maximum scores).

But I was never under the illusion that this constitutes working knowledge. I was able to come up with solutions for some problems only because I had some basic knowledge memorized, which allowed me to effectively manipulate ideas and concepts which I did know of. Even then, I used to semi-joke how the hardest thing in theoretical math is all the memorization required.

If you've ever explored any scientific field deep enough, you'll know that it's festered with tricks found by accident and roundabout ways to get to a solution that, if you haven't seen it before, you have no hope of applying in practice.

Or you might think that consulting a book or two (or Internet) will allow you to prove Fermat's theorem while you are being tested for 2h.