I agree. As an example, when I learned C++ I already knew the principles of object-oriented programming (from Smalltalk) so learning the OO parts of C++ was rel

I agree. As an example, when I learned C++ I already knew the principles of object-oriented programming (from Smalltalk) so learning the OO parts of C++ was relatively easy for me. Learning a new language, provided you already know the concepts the language uses, is mostly a matter of learning new syntax.