Having a deep understanding of the environment in which your program runs (be it the language runtime, or the machine itself) is always an advantage. It doesn'

Having a deep understanding of the environment in which your program runs (be it the language runtime, or the machine itself) is always an advantage. It doesn't necessarily follow that you will use that knowledge to be "clever". It helps you avoid pitfalls and debug strange behavior more easily. It helps you know when to use them, and when NOT to use them. Someone who only knows how to program in practice is ignorant, and someone who only knows the "deep stuff" and can't program effectively and cleanly is just a "language lawyer".