I imagine if I'd managed to actually memorize all of C++'s initialization rules, I'd probably have to write a book too just to get it all out, or I'd lose my sanity.
Then you can proudly put “C++ initialization consultant” on your resumé and get paid $1000 a day fixing class constructors at Fortune 500 companies.
There are no limits to how much of an specialized expert you can become in C++.
Knowing all of it just isn't possible from my experience.