Along with most things in life, the human mind remembers the things the opposite of how someone might think it would. Counter intuitively, the more frequently you see something, the weaker your mind reinforces the memory at each exposure.
This is why when you are stressed about a test and constantly study and come test day you struggle to recall what you studied. I take this one back to yet another evolutionary analogy.
Evolution of Memory
Lets say a caveman comes out of his cave and sees a bush with berries. He eats the berries and; bam, he has diarrhea. So this caveman comes out of his cave every day and sees this bush and is reminded that they gave him diarrhea, don't eat them. Since that's frequently reminded to him externally his brain internally sees no urgent priority to save this in his memory. So the memory is lightly reinforced each day.
So if this bush died and a year later he stumbled across another berry tree like that one. He might have forgotten, then eaten the berry again causing diarrhea. Now of course the caveman remembers the original berry tree in front of his cave. Now his brain knows that he is no longer frequently reminded of this berry externally, so his brain will heavily reinforce this memory and he will be very unlikely to forget in the future.
So if you want to effectively study for a test, do a quick overview, then the next day or a few days later overview it again and I personally guarantee you will see test score improvements as well as a lot more free time. Also eating chocolate or any scent while studying and then again during the test will cause improved recall and essentially better test scores.
There have been studies that show two weeks is the peak waiting time for memory reinforcement. So lightly studying two weeks ahead of schedule would be a very good way to improve your recall come test time.