Correct, but it can be a fun exercise, if for nothing else than the curiosity alone. Learning basic circuit theory leads you to diodes, which then leads to transistors, which then leads to op-amps, logic gates, etc. which leads to computational logic units like the ALU, etc. Before you know it, you have a very, very basic computer going on.

Either way, it's the core process of engineering - applying theory, and breaking up complex parts into more manageable chunks. Same goes for the car engine - it's a complex piece of machinery, but still a sum of its parts.