It all depends on whether you understand what it means "to understand". There are two schools of thought: School 1: User's knowledge (this idea goes all the w

It all depends on whether you understand what it means "to understand". There are two schools of thought: School 1: User's knowledge (this idea goes all the way back to Plato). You know how to use existing CPUs and existing programming language. This is akin to understanding the existing limits of existing technology. School 2: Maker's knowledge. You know how to invent CPUs and programming languages from first principles. The latter school inevitably leads to Wadler's law: semantics. It leads to asking "What is it that I want to express and why?". This mode of thought pre-supposes pragmatic/goal-driven intent.