which means memorization
which means memorization
For example, in third grade my class had to memorize the multiplication table up to 12x12, but we didn't have to memorize that multiplication is really just a shorthand for repeated addition, so by eighth grade there were kids in my class that didn't understand why I wrote 6x5 instead of 5+5+5+5+5+5 in certain cases; they were also amazed that I managed to get the right answer even though i didn't do the problem the right way. We also had to memorize the squares of every number up to 20, but we didn't have to memorize the fact that squaring is a shorthand for multiplication of some number by itself, so some kids in my class could tell you that 15 squared was 225, but had to use paper and pencil to tell you what 15*15 was. And don't even get me started on kids who knew that 9x7=63, but had to use pencil, paper, and long division to tell you that 63%9=7.
A better example to express your point would be multiplication tables. Why memorize a list of multiplicands and their products rather than learn what multiplication means so that you can generate them on the fly and only memorize as a by-product of common use?
In order to learn something usefully, and be able to retain that knowledge for years to come, you must have a fundamental understanding of the underlying principles.