If we look at the martial arts as a language then we get a lot more meaning and understanding of our training. Any language is a very sophisticated and useful tool based on many words with different interpretations. One wrong word can lead to a misunderstanding. If we equate this to martial arts the similarities are incredible.
The point here is there are many techniques (words) just so there are many techniques in the martial arts and they may all have different interpretations. In fact, there are so many out there, it is impossible for one person to be able to learn them all. Of course, each Instructor has a way of teaching and each school has a syllabus which is the minimum requirement for each progressive level, however, sometimes certain techniques may not suit every individual because not everybody is made the same. As the Instructor, I, sometimes, need to modify techniques for certain individuals. These individuals may not necessarily be lacking physical ability but they just don't gel with a particular technique. Sometimes, it's just a matter of explaining it differently or modifying it. My favourite saying, ‘problem solved!’
BJJ is such an evolving ‘language’ with new techniques coming up almost every day. I ask, does anyone know every single word in the English language? Of course not, but everybody tries to learn as much as they can. So, too, in the martial arts, so there is no reason to worry for not knowing everything.