I clearly recall memorizing the times tables when I was young. It suddenly dawned on me that "times" wasn't just a word, it meant adding the number so many times. I no longer needed to memorize the table, I just applied the rule.

Some university engineering classes present formulae and tell the students to just apply them. This is disastrous in my not-so-humble opinion. Where the formula comes from should always be taught, so students understand the formula and the assumptions it was derived from.