The most important thing in mastering a subject is to know all the vocabulary and terminology involved in that subject and to be able to express oneself using that terminology. I have been encouraging every student I deal with to make their own vocabulary list, with the word, a brief definition, and a sentence of their own creation. Some students do this, others neglect this advice. Next, one must think about the subject -- that means spend some time thinking over the ideas in that subject, and how they relate to other subjects. Another thing is to work a lot of problems such as in math, geometry, physics, chemistry, or answer a lot of questions such as in history, or to practice speaking or listening to a foreign language when studying another language. What I am suggesting is that a student who wishes to succeed and excel must go beyond teacher assignments. The student must take charge of their own learning. The student must keep vocabulary lists for every subject -- must go beyond classroom assignments in order to truly excel and not just plod along.