Well, I am even older -- started on unit record equipment and really understood it. Later, I wire-wrapped a single board computer in order to learn about TTL. But I did that without understanding the physics. I could use relays and TTL chips, but did not understand them. Same with programming -- started with low-level assembly language then moved to higher levels of abstraction -- first IOCS routines then Fortran. Today we program at still higher levels of abstraction.
But, I never could have built a relay from scratch let alone a TTL chip. Even us old guys were far from self-sufficient and capable of restarting "the machine" if it failed. How long did it take people to get from mud to pottery, rocks to steel and concrete, raw meat to cooked,sheep hair to shirts? We are all extremely narrow specialists.
Also -- you've picked a tougher sounding life goal than Doug Engelbart did.