I used to think memorising facts was a waste of time.

I'd say things like "why would I spend time memorising facts when computers can do that for me?" I thought there was a stark difference between "memorisation" and "understanding how things work". The former was for people who wanted to pass tests, and the latter was what smart people dedicated their time to.

What using spaced-repetition software has taught me, however, is that memorisation and understanding are tightly coupled. Storing facts in my brain increases the amount of connections I can make, which greatly improves my ability to think.