Do I know how to make a CPU? No. But you know what I do know- how to use transistors to make gates. How to use gates to make flip-flops, ALU's, and memory-mapped IO. How to make a pipeline out of flip-flops and ALU's. So on and so forth. Nobody can envision a whole CPU in their head right down to the gates, they rely on many layers of abstraction.
Do I know how to make a CPU? No. But you know what I do know- how to use transistors to make gates. How to use gates to make flip-flops, ALU's, and memory-mapped IO. How to make a pipeline out of flip-flops and ALU's. So on and so forth. Nobody can envision a whole CPU in their head right down to the gates, they rely on many layers of abstraction.