I'd say that it takes some time to get familiar with some abstract concepts like pointers, classes, methods, structures etc... if you're new to this. I'd say it's the "metalinguistic" part of C++, in my opinion the most dry, as you don't are rewarded by immediate results in the sim.
Else, when you got the compiler set up (see the famous Computerex video tutorial), making some mods to the ShuttlePB sample is rather straightforward. And from there, you can try new stuff, more advanced functions etc... I'd say it's the "syntaxic" part of C++. The good news is that Martins provides us a "dictionnary" (the API reference), and that you can find exemples in existing samples.
And, beyond that, C++ is such a vast thing that you probably can't learn it in an exhaustive way. So you always learn new "vocabulary". And in the same time, you learn to organize it better (metalinguistic part)...
So as said above, you never stop to learn. :yes: