In most advanced subjects, (pretty much hight school and up) to memorize formula and facts actually does require quite a bit of abstract knowledge to use them. ex. Just because you know who Aquitaine and Claudius and Nero are and when they ruled can you write an essay or even answer simple multiple choice questions about the decline and fall of the Roman Empire. That would take some outside education and a fairly smart person without a whole lot of structured reading.

Outside of the liberal arts (and even those really take a decent amount of time to grasp) in the math/science/engineering fields. The reason that they often have problems from the end of the semester on the final is that the rest of the time is building up understanding on which formulas to apply in which case and how to correctly use them.

This means that if you innately "get" the subject matter well enough to just pass a final, doesn't that mean that the class was a waste of your time that could be better spent on a subject that you do not have a natural talent for?

Having fresh drinking water, forget needing food or gas or god, no water for 3 days and you are beyond all of these problems. Desalinization is impractical because of power demands.