> Obviously there are equations and pure facts. Those you should simply look up when needed. In math, at least, part of the difficulty of higher level problem

> Obviously there are equations and pure facts. Those you should simply look up when needed. In math, at least, part of the difficulty of higher level problem solving is that you simply need to have a large number of definitions and theorems memorised to be able to do anything interesting or difficult. And you need to have seen (and remember!) examples of things. This lets you reach a higher level of thinking where your intuition about what is and isn't true is much better. "Look at up when you need it" doesn't work if you don't know what you need. Typing out math doesn't really get my juices flowing. I freely admit I have no real evidence for this.