I call it the Rule of Twelve, and it states that if you know twelve concepts about a given topic you will look like an expert to people who only know two or three. If you learn more than twelve concepts about a topic, the value of each additional one drops off considerably.
Allow me to be the first to confess that twelve is not a magic and inviolable number. It just sounds better than The Rule of Several, Give or Take Two or Three, With Lots of Exceptions. So don’t get hung up on the number twelve.
The power of this rule is that seemingly impenetrable topics are less intimidating if you know there are only a dozen concepts to learn. And often the details of a subject are unimportant if you know the big concepts. Let me give you an example.
As I’ve mentioned, my wife and I are in the process of building a house. One of our goals was to make it as energy efficient as practical, while still having the features we wanted. And that meant learning the twelve-or-so concepts of green building that would get us where we wanted to go. Those concepts aren’t neatly listed anywhere, so you have to flail around until you scare them up. For example, I spent a huge amount of time trying to figure out the best type of insulation for the walls. I looked at everything from SIPS to hippy ideas about hay and compressed dirt, to blown-in cellulose, to standard batting. And it seemed no one could give me a definitive answer on what R-value was best for a home in my area. Big developers used whatever was cheapest and met code, because they didn’t have to pay the utility bills after their homes where sold. And every individual home builder and owner seemed to have his own theory on insulation type.
Eventually we talked to some engineers who explained some of the twelve concepts to us, and that made the decision easy. It turns out that in my climate, no matter how you insulate the walls, it’s the windows and roof that will determine (mostly) how much heat penetrates your house. There was never a need to learn about exotic wall insulation methods. We just had to make sure we knew the twelve concepts about windows, roofs, thermal mass, orientation to the sun, chimney effect, and a few other concepts more important than wall insulation.
If someone is explaining a subject to you by listing lots of facts and examples, without explaining any of the twelve concepts, you probably aren’t learning anything useful.