Taught some pinball repair classes a few times. During tournaments we'd bring in techs from all over, but we RAN OUT AND HAD TO GROW OUR OWN, so I started off with coils and power supplies and how-the-hell-do-an-electron-go, y'know, the fundamentals.
Did a quick bit on bridge rectifiers and smoothing caps and coil drive transistors and then held up one of these lads and said right let's fix one of these and everyone, all these pinball teching newbies, took this Indrawn Breath because HOLY SHIT JUST LOOK AT IT, you mean we gotta UNDERSTAND that?
I said don't worry. The biggest, most complicated, most intimidating system you can think of, is made out of smaller, simpler systems, and then those systems are themselves made out of even smaller, simpler systems, until you get right down to stuff that's very understandable and very fixable by the average person, and if all the little easy bits work then the big complicated thing has no choice but to work.
I'm posting this now because someone just called that post "philosophy" and it's not philosophy it's just literally how pinball machines work lol