The Visible and The Invisible
There are the visibles and invisibles in Taekwondo. Most people pay attention to the visibles only. The visible are also important but, if unsupported by the invisible, they cannot work alone. By contrary, the invisible work in many cases even with some faulty visible factors.
In this sense, the invisible are more important in technique.
In Taekwondo the visible are not so many. Its almost part can be written in a big textbook, and the whole content can be read in one or two days. If you learn Taekwondo you can memorize them in several months, or at least, in a year or so. But it is quite certain nobody can learn Taekwondo completely in that period. Why? More part of Taekwondo belong to the invisble, and I say, the invisible are the essential part of Taekwondo.
If we compare Taekwondo to a structure of human body, I believe this is quite good analogy, the visible are like the bones. The skeletal structure describes human body correctly in some sense. It can characterize what is difference of human body from that of another animal and what is shared features. But it is also true that it is never sufficient to describe humany body only with skeletal system. Instead, with the knowledge of skeletal system, we can learn main axises of Taekwondo, and know what is more required to learn full knowledge of Taekwondo.
Just as we have to understand inner organs and muscular system and the likes are necessary for the living human body, so we have to understand what I call "Invisibles" are necessary for the true Taekwondo. And just as they are more than the skeletal system in quantity, so the invisible are more than the visible in quantity of knowedge and practice.
Without this knowledge of the invisible of Taekwondo, you as an instructor will not be able to find abundant thing to teach your students, and it will bother you what you will teach them next time.
But it has been difficult to recognize all the factors of the invisble. For nobody suggested the system of the invisible factors of Taekwondo, or any other kind of martial arts. The Korean traditional philosophy made it possible, so you can now see the system in On Samjae and Kang-Yu. (Particularly, refer to Ch.2-1) If you want see a picture of the overall system, refer to "Structure of Taekwondo Philosophy."