Kids are looking lost and panicky over their second common test paper. Essay exams drive them nuts because their instant response is to assume they know nothing about the topics the questions cover. But that's exactly the point of essay exams, particularly for GP. There is no other reason to take GP than to train in crafting out a rational answer to any question to which our initial response is, "how the ^%#$ should I know??"
GP is humbling that way. Every essay begins with zero knowledge. Unlike the other academic subjects the kids are taking in the JC, it is the question that is more important than the answer. A GP essay is little more than the breaking apart of the question and examining or exploring the intricacies of each little component and then reassembling it all back within the context provided by the question. This is excellent preparation for the Uni at which every question in any subject they will encounter will be structured more or less like this.
It helps to have lots of background knowledge of the subject. The more knowledge we have the more facets we can appreciate of the question, but having comprehensive knowledge is not mandatory. There's only so many bits we can play with in the 800 word limit.
The less the knowledge, the higher the fudge factor. It's best to keep the knowledge up, of course, but it's sufficient to strike a balance between the two. That's the real skill, and that's how most questions get answered in the real world, anyway.
The best questions are those that answer themselves. A good GP student will be able to identify such questions and let it take the lead in coming to an answer.
The higher up the education ladder we climb, the less we know, we realize. But that's great! "I haven't a clue" is the best way to begin answering a question. In fact, it's the only way.