Learning the martial arts is often likened to learning a language. You can memorize the alphabet, yet still be unable to form words. Individual words can be mastered, yet grammar can remain poor. Writing and speech can be technically proficient, yet you may still be unable to write good poetry. In the martial arts, learning all the techniques and routines does not automatically make you a skilled fighter.
Like poetry, only so much can be taught. It is up to the practitioner to make good use of his “words.” While instructors may be able to bring students to a basic level of proficiency, it is ultimately up to the practitioner to make his skills effective. Just as a good poet can gathers words and ideas from experience, a good martial artist must be able to learn from observation and experience. In this way, any school or teacher may be of use in progressing your skill. You can observe the strengths of an instructor’s techniques and extract the essential elements, adapting them and eliminating the faults.
You must develop your own sense of what is practical. This can be learned through live experience, testing and competition. You must constantly test your skills to ensure they are developing properly. A single fight, even a sparring match, can teach you more of the true nature of live combat in a few minutes, than years of training alone in a vacuum.