Yes, but some knowledge is a requirement to really understand something. Trivial example: can you really understand addition of numbers if you can't remember how to do it?

Pure memorization of facts is also really helpful to creating new understanding: Have you ever read a textbook that stacked definition upon definition and at some point you can't really keep up anymore because you're going back to the previous paragraphs all the time? At that point, pure memorization of definitions (even without understanding them really) already helps massively to reduce cognitive overload and makes forming new understanding form the rest of the text even possible.