You have to remember, a micro-processor isn't some 'magical' chip, it's actually built from basic gates and flipflops, using individual transistors etched on the silicon - so micro-processors are similar to these inside, but probably far more complicated. Also remember, someone had to design the micro-processors in the first place!.
I've got a book somewhere, I bought it back in the 60's when I was at school, it's called something like "Build your own computer"?. Essentially it shows you how to build a crude 'computer' using flipflops and gates, allowing simple binary addition etc. As I recall it wasn't a programmable device?, and it was built using all discrete components (it was pre-TTL, or even RTL).