I agree that no amount of revision will help you to pass exams at degree level unless you have the intellectual capacity, but it is often useful to refresh the databank. Armed with that you can go into an exam room and weave a rich tapestry around the most trivial of data (I'm talking Arts, rather than Sciences here). One of the most boring aspects of being a teacher, especially at university level, is marking. Page after page of students regurgitating what they believe the lecturer wants to hear. Throw in a statement which runs counter to received wisdom, justify it with some specious sophistry, and his eyes will light up. You will get extra marks for sheer nerve, if nothing else. A story is told of the History department at my university (which awarded only one first class degree over a period of twenty years) where a lecturer awarded a very mediocre answer with a grade A. When asked to justify his marking at a moderators' meeting he replied, "He used a semi-colon, and correctly, too!"