In order to learn something, you must understand it. You might become so insightful and facile with the ideas that it appears you’ve memorized them, but that’s just a side effect.
Rote memorization can be done in some fields, and you can even recite what you’ve memorized to someone else who can memorize it.
For example: You can’t learn alphabetical order, you can only memorize it.
On the other hand, memorizing anything that you’ll need to build upon, improvise on or improve is foolish. You’ll need to do the work of understanding it instead.