If you are really a programmer, one who learned the fundamentals of Computer Science, this isn’t really true. If you understand the concepts of pointers, references, stacks, buffers, recursion, threads, blocks, functions, types, casts, regular expressions, automata, and Turing Machines, you can teach yourself any language or framework. Even Cobol on IBM mainframes. If you’re a Visual Basic jockey who hacks and kitbashes someone else’s scripts until they sorta work or at least don’t crash but you don’t know why, not so much.