another dumb question…
But if I masted the 'docs' of jME is it possible that I would have masted jME and could do anything I wanted w/ it?
Actually, the documentation of jME is not as good as the tutorials and mini tutorials (Hello*, Test* and Lesson*) I would say it the other way around… if you happen to master jME, I would ask you to master the docs (i.e. write them, because they are lacking, outdated or simply not enough). 
The best way to master jME is to look at the source code for every class you're using.
source code, is that the docs?
Pretty much… welcome to Open Source… Learn by code would be a nice term to coin (or maybe someone has already done it? )
RTFS is still better than RTFB 
source code in that case would be the java code that you're calling from your code to make things work…