It's obvious that I know the subject matter.. I just cant converge on an answer come test time...

Then it's not obvious at all. Everybody occasionally blanks. What you seem to be describing is a reliance on "conceptual understanding" at the expense of actual problem solving skills.

Both are important. Rote handle-cranking by itself doesn't make an engineer. But if your response to a "curve ball" is to sit and stare waiting for "inspiration", that's your problem. You find answers by attempting the question - good old fashioned hard work until it falls into place.

I suspect /u/Untarr is right - if your study method involves any sort of "oh, I just need something to start me on the details" (be it remembering past problems or a glance at the solution), or "and the rest is obvious ...", stopping short of a final answer, then you really don't know how to solve problems. The details are the problem. Conceptual understanding is great, but that is often the easy bit - knuckling down and applying it is hard.

I could be wrong. But it is difficult to say why you are missing obvious details without knowing how you currently study. But the arrogance about "obviously knowing the material" when you can't actually solve the problems probably isn't doing you any favours.