Indeed, C++ is different from most languages (other than C) because "knowing C++" does not mean just knowing syntaxis and standard library API but implies understanding of how the source code is turned into bytes inside an executable image. A Python or Java or whatever programmer could be writing books and praised as the language expert without slightest idea how is memory allocated, a C++ programmer who does not know that is probably going to work in some legacy shop supporting an ancient MFC/Qt data-entry app.