[bsder]

I think people are confusing "memorization" with "practice". "Practice" is really important and "memorization" is both the prerequiste and result of "practice".

I often tell people "Calculus is just algebra. However, it's fast, repeated algebra. If you aren't excellent at algebra, calculus is going to be terrible for you. On the flip side, calculus forces you to use your algebra so much that you get much better at it."