Budo the philosophical practice of martial arts is not about fighting but, about mastery. Mastery comes in two forms and these forms are associated with intelligence types...
There are two types of intelligence Practical Intelligence... a mind that remembers facts and the application of information. The second Intelligence is what we call, Analytical Intelligence this is the ability to Remember information and the ability to apply it in abstract ways. What we call Creative Intelligence.
Depending one's motivations and type of intelligence rank being a Master and Mastery have different meanings. To someone with practical intelligence being a master is a level of ability or knowledge and, mastery is a dogmatic context of tradition and codified technical routines.
To someone with Creative Intelligence, mastery is a journey and it doesn't end. Rank is an abstract title related only to art and organization. Because to the Creative Intelligence, they are trying to remember someone else's definition, dogma or codified system. The analytical mind is dissecting things, try to view the same thing from different angles and prospectives.
Analysis is how the mind learns... Some minds simply learn "Fire is hot and hot hurts." other minds learn "Fire is hot and hot hurts." Then those minds ask "Why is fire hot and why do we experience pain?"
Omoto Ryu Budo was taught to me as a system for the Analytical mind. It was not enough to understand, to do something but why and adopt it to different levels of stimulus. It was not enough to think but to experience and then analyze and understand. This leads to invention of new techniques, combinations and training methods. It is a living, evolving and personal art form...
This is why there is no Soke in the Omoto Ryu tradition. Even though it claims roots in Koga/Koka City Japan, it is a modernized form Bujutsu & not a complete codified system of dogmatic structure. This why men like Ken Shamrock, Chuck Norris and Heilo Gracie (RIP) don't run around calling themselves "Master" in the sense of a dogmatic rank structure.
There are men in the world who... Because of their age alone, I would hate to hit full force because I would fear injuring. Same men regardless of their age I wouldn't take lightly in a fight because of their wealth of knowledge, level of experience and regardless of age know their not to be taken lightly... They are masters in their own right.
What is mastery? Mastery is the ability remember knowledge/information and to apply it. To the Practical Mind, it is being able to fight (hence why I mentioned the three names I did) and rarely does it go further then this... But, that is Practical Mind.
These same men also represent another element to martial arts that of application of the arts to life... The Abstract of the Analytical Mind, this is perhaps what Kioshi Omoto meant when he told me "Mastering martial arts is easy, mastering life is not so easy." Even Rickson Gracie has said "I think there’s a philosophy behind martial arts, which should go along with training and go hand in hand with a fighter’s routine. Nowadays, the first principle is that there is no philosophy. It’s about cross training. You’ve got to cross train to be able to fight, kick, and hit. Every rule draws you to an extreme sport without a code..."
To further draw off of Rickson Gracies comment here, that code is what gives martial arts their purpose outside of just fighting. That is the meaning of Budo, and mastery of Budo is mastery of life through the Warrior's Code.