It is one thing to understand the principles and concepts of one's art intellectually -- and another to put those principles into practice. If one doesn't put the principles into practice, there is no way for the art to mature. If the principles are just something understood with the mind, no matter how well one can explain them with words, then the principles of the art are just in the mind, and not in the body. When one's art is not using the principles in both the body and the mind, it is incomplete. Just as when one is hungry, one needs to actually eat food instead of just talk about it -- in learning one's art, one must both apply the principles and understand the principles, getting them into the whole being -- body and mind. This requires diligent practice.
When one practices, one must strive to implement the principles as clearly as possible, not just go through the motions. Just practicing without applying the principles accomplishes little -- but applying the principles of one's art in practice, always yields deeper, more profound results.
When one assiduously implements the principles, one touches domains which are about quality, nobility, and essence. Implementing the principles with vitality and sincerity makes one's art about self-cultivation and empowerment, and raises the calibre of the endeavor to a higher level. Implementing the principles makes the enterprise a spiritual quest and an event which develops one beyond mere bodily strength, coordination, and stamina.
Implementing the principles makes the endeavor an "art", and brings zest and character into play. One cannot just go through one's movements sloppily with little care. One must pay attention, focus the mind and body together, and be deeply conscious. One must apply oneself with every fiber of one's being, instead of being only partially involved. Implementing the principles can expand one's being, raise one's consciousness, give purpose, and take one to new and higher levels of existence.
Practice well. Practice...and implement the principles.