What does it take to be considered a master? First of all, it takes humility. Those who say they are probably aren't. Secondly, to gain a level of proficiency to be considered a master takes a lifetime of study. Regardless of one's genre, one has to put in the time. Over the years I have become a fan of the famous wilderness instructor Mors Kochanski who many consider to be the father of the modern Bushcraft movement. I say fan because I merely read his books and articles, but don't practice his skills.
His lifetime of study makes him great, but his down to earth humility makes him a master. He has come up with numerous wilderness survival techniques over his career and he is someone who seems readily accessible and willing to pass on his knowledge. One of my favorite Mors Kochanski sayings is, "The more you know, the less you carry."
This quote is apropos for martial artist too. What he is basically saying is that knowledge is power. With knowledge comes options. The more we study and train, the more options we will have and thus the less we will need.
Below are two videos. The first one is of an ingenious winch Mors Kochanski came up with. The other is a video of him candidly talking about how to pick the best knife. You can see from that video his level of understanding and his willingness to teach others.