The Importance of Understanding the Fundamentals of Network Protocol

RPC can't just be some magic function that returns a component. I want to be able to explicitly define what the form action is going to do, which has to point to a URL. So my question is, why do I need to understand the underpinning fundamentals of the network protocol and the way that data gets marshaled or serialized, de-serialized over the wire? Why is that really fundamental knowledge that I need to have? I'm not sure.