We memorize in order to facilitate learning, so we can function with the demands of the field. Memorization is not an end in itself, and it does not constitute learning. But when you use this information, you won't forget it. Every field requires memorization, and most fields -- biology, history, physics, political science, languages -- require far more. We are only able to solve problems if we are familiar with the necessary terms and laws. To improve your memory, don't trust your recognition memory when it comes to a test. Practice writing out the definitions and theorems, and make outlines of the major points of the theory. Check back to your text for accuracy. It is easy to think we know something until we attempt to put it in writing. By practicing studying continuously in this way, rather than cramming at the last minute, you will find memorization will feel more naturally like part of the learning process.