I have always been inquisitive about how things worked in general, but I think when it came to cars many times it was either obvious (part broke) or could be diagnosed by replacing parts, either way there were (perhaps are) a number of things/systems I never dove too deep on (obviously the alternator/charging system was/is one). I understand how it goes in and how it to be used but I never investigated what made it work or perhaps better said how it all worked.
When I started putting EFI on cars, I had to learn that from the beginning and am still learning (and probably will be for a very long time). It was very intimidating in the beginning but I read and talked to people and slowing began to get a working knowledge of them. I am certainly no expert on them but I am not afraid of them anymore either.
Life is funny, I could have certainly used much more knowledge when I was 18 and running the streets in my 74 Challenger (transplanted 440 6 pack) but I managed to get by. Now that I am much older (like 40 years) I have the tools, shops and knowledge to do so much more in a much better way; seems like life is backwards sometimes..