No matter how well you learn something, if you never access that information you will probably forget it. If you want to remember something, you need to review it from time to time to keep it fresh in your mind.
Review can also be very helpful immediately after learning something, because it can help solidify the important facts and make it easier for the brain to identify what to remember. You can use this to your advantage by making sure that you set aside some time at the end of a study session to review what you have learned. Just going over the main facts in your mind will be very helpful. You might also consider doing this after a class lecture. Take a few minutes to review your notes and go over the instructor’s main points.