I am currently a math/physics major who is almost done with his mathematics degree (I am a junior but I did much math and should be able to complete my degree in just three years + one quarter versus the normal four). However, I will still be taking another year or two to complete my physics degree. I am worried about getting into a graduate school to study the topic that interests me (quantum gravity and its application to cosmology.) Despite the fact that I have PASSED all of my mathematics courses, my understanding of most topics I feel is pretty poor. I have forgotten much of my linear algebra, almost all differential equations, even the complex analysis work I took recently is fading from memory. I think this is in part because there is simply so much stuff to learn and if I don't practice it all the time, I will inevitably lose some of it... but I think another issue is that I just don't know the subjects that well. I feel like I passed much of math without actually having to learn the math. Sort of a 'plug in numbers, memorize theorems, but not worry about having to understand the deeper aspects of it'. Regardless, I am contemplating the following idea and would like some input/advice. When I finish with my B.S. in mathematics, while I finish my physics degree up; I am thinking of re-learning calculus, linear algebra, differential equations, as well as complex analysis and abstract algebra on my own so that I can grasp the concepts involved moreso than I do now. Also, with my GPA sitting just above a 3.0 I think I am going to have to depend on research and a great GRE score in order to get into some good graduate schools. Perhaps this re-learning; along with practicing GRE exams (taking some sort of prep-course) will help me accomplish this. Maybe, if I needed to take this to an extreme I could get a job for a few years with my bachelors degrees while going over the material I spent four years learning; and then judge if I feel ready or not based on whether I can complete those prep GRE's. Thanks for any input/advice! EDIT: I have also not taken any probability/statistics courses (I didn't have to; and statistics doesn't interest me). Do I need to have a knowledge of this for the GRE?