I decided I could fix my own cars when I “realized” that ‘if someone else can do it, I can do it’ as well. Turns out I had to learn a lot, but I learned it.
Fixing cars is of course learnable; we all know that mechanics exist. But computing hardware is usually built by really complicated machines. I honestly don't know whether it's possible for a person to make a CPU.
Click on Nana2Tetris in the link above. You'll find out a good bit about it. Modern CPUs are enormously complicated. Machines from earlier eras tend to only be of only middling complexity.
