Math professor here. It is good if your teachers explain the why, but it is even better if you fill it in for yourself. Read your lecture notes, or your textbo

Math professor here. It is good if your teachers explain the why, but it is even better if you fill it in for yourself. Read your lecture notes, or your textbook, with a critical eye. "Why are they doing it this way? Why would anyone think of this?" etc. If you think your book or prof is being obtuse, try to figure out why you think that way. I curse at math books sometimes... Instead of refreshing the correct technique and then solving the problem, try solving the problem without first recalling how to do it. Perhaps you will figure out the solution and invent the solution method yourself. If you are more like me, you will fall flat on your ass and produce five pages of calculations that go nowhere. In either case, you should then read the book's explanation and you are much more likely to remember it. And that happens to everybody. I am constantly having to relearn stuff. If you think it's difficult --- good, you're doing it right.