Memorizing means that you have committed ‘something to memory’, learnt by heart, with the intent of later recall when the ‘something’ is to be used in comprehending, applying, analyzing, synthesizing, and evaluating. The idea is that you can recognize, recall and use useful, other knowledge related to what you have memorized. The thing memorized can be a trigger for other internal or external knowledge.
At the higher education level, students are often asked to memorize many different types of things. Krathwohl categorizes knowledge into four types: factual, conceptual, procedural, and metacognitive (D.R. Kathwohl 2002).
There are some things you need to remember and there are other things that you do not. In the latter case, we are reminded of an observation made by Peter Drucker – there is nothing more futile than doing something efficiently that should not be done at all (Drucker 1963). If you can look it up when you need to, when you need to apply, analyze, synthesize, and evaluate, why place a great deal of emphasis on memorization during a course?
So, not every piece of knowledge has the same utility or value in the cognitive process. Some knowledge you should have at your fingertips, instant recall. At times, different levels of knowledge are necessary and it is not always possible or desirable to start from first principles all of the time.
There is a tradeoff. How much memorization is needed and how much is not. There are old adages about teaching someone to fish, various versions, but the message is the same. Laozi, 4th century BC, is one potential source of the message. The message is clear and has been repeated and noted by many, including Bloom's report: you do not need to know everything or be given everything, there is key knowledge you need to know. This is the philosophy behind Threshold Concepts. After that, you should be able to figure it out, learn what additional knowledge you need. However, as noted in the Bloom report, it is most likely that most students and instructors would prefer the easy way to learn and teach, and that means you focus on memorization at the cost of 'better' learning. Teaching cognitive skills is more difficult for both student and teacher.
An instructor should be selective about what knowledge is taught and expected to be retained after the course (not just till after the final exam), and how it can be learned and retained. Although, we know from the predictions made by Bloom and his colleagues that many instructors will find lots of facts and basic knowledge to teach and then assess; it does make the job easier if you do not have to muck about with understanding and comprehension.