When I thought of examination, sometimes it's the matter of luck + bullshitting the right stuff with logical reasons because your results is determined by the state which you were in during your examination.

Whether study or not, even if you have vast knowledge about that topic itself, if your points doesn't get through the lecturer, that's it. Smart people doesn't need to study so hard and get A for essay module easily while the rest are just studying and still doesn't write what lecturers want.

So in the end, don't study, just bullshit!