I have one question and I hope to get my answer soon.

I have almost completed my Pak. Affairs, Sociology, Journalism and half of EDS. I try to highlight the main concept/points of each topic and then I try to memorize it. But then, I feel I am forgetting previous stuff as I am learning new stuff. Can anyone tell me, how to keep the previous stuff in mind and concentrate in new stuff because there are still 4 months in exam and I am scared that I might forget everything by that time.

Please do give suggestions.

Thanks