I think Pete is right its the little things that make the difference between Johnny Average and a decent installer, I was lucky and, the thing is (and this is why I LOL at the whole 'part time ambo driver' slur)
is that for many years, long before I knew anything about ambulances other than you can help yourself to cool drugs and use the blue lights to get between McDonalds branches
getting free coffee in the lonely hours between massive car crash jobs, I spent years post C+G exams as a contractor* for a very decent, well respected, do-it-by-the-book firm and
learnt just as much from that as on my own, before then, sure I had passed my exams and did rewire a few houses, but stuff you learn on the job like doing conduit neatly and properly, MICC termination,
the difference between scruffy junction boxes and doing it right, you don't get taught that at college, and other more complex stuff, I don't know like all the peculiar rules around
earthing at special locations that kind of thing. Of course, follow the wrong firm and you'll likely pick up really bad habits, but I was lucky, without that, yes I'd probably convince myself I was as good
as anyone else, but I wouldn't really be in the position to tell. After all, if I'd only seen the shiite work we used to encounter without having done it properly myself, I'd probably just assume the shiite was normal!
*I should say a contractor with only about 5-6 people on the books, 3 of them directly employed, so we often worked together as a team so that made all the difference for picking stuff up...