I'm the original poster, the one who asked these questions. I just wanted to clarify that of course I know that I can use a handheld meter. In fact, I have a very good Lumu that has never failed me when I felt that I had to use it, especially with tricky situations (for instance when there's more than one light source).
I know that a lot of people have developed their techniques measuring light almost exclusively through years of trial and error. IN other words, experience is a great teacher. I was just wondering if some of the results of that experience could be shared around for those who don't have it yet. I appreciate that some people have taken their time to help us avid amateurs out in our own personal journeys in photography technique.
However, I find it quite disrespectful to assume that people who don't follow the "true" ways of calculating light with meters are either liars or fools. Obviously, it is a difficult ability to be acquired but most helpful without any doubts. As in everything else in life, information and curiosity are inherently part of what makes us humans, even when not immediately practical... and of course, this concerns me personally as my own everyday life (I am a PhD candidate in sociology and history) would have no meaning if I thought that "non-useful" information is stupid.