What is the fundamental knowledge that the average, or above-average physicist must possess? Put simply, even a subject as rudimentary as undergraduate level classical mechanics teems with so many formulae and so many derivations that I find it incredibly mind-boggling that a physicist should remember all of these details at all. Can someone kindly enlighten me on these processes: 1) Taking an examination tested on a certain subject(s) in the undergraduate and graduate level; to ace the written examination with excellent scores (we exclude any formal assessment of experimental techniques for a moment), must one actually oblige himself to remember everything that is to be tested? In fact, I think I have a better question: WHAT is being tested on such written examinations at all? Do questions on the examination assume similar forms to textbooks written on the same subject? 2) I extend this perplexity of mine to real-time physics careers. Is there some form of knowledge that physicists (it will be fantastic if anyone can relate to specific examples of a theoretical physicist's job - the one who investigates such things as quantum gravity and modern cosmology) must possess at all? 3) Generally speaking, how much does a theoretical physicist working in the academia earn per annum? How much does the average physicist earn per annum? I apologize if I defined some of these uncertainties quite ambiguously; I've had no formal encounter and no experience with such issues whatsoever.