The question popped into my mind.
I know that Bruce trained very hard,he had a strong desire for martial arts.
Many people think he is the greatest martial artist of our time,for some,it is an usual “fact” of life.
Some of us train for all the time of our tiny lives (then we…if we trained hard enough,become what people call a MASTER)
My personal belief is that one never masters an art,there is always more to learn.
When we compare Bruce´s experience to the experience of such men like Morihei Ueshiba who trained for all of one´s life and become official masters,it makes me think if Bruce was a master at all?
There’s no such thing as a master
I would agree that there are no masters. Just teachers. To master IMO means to fully understand and apply. Ueshiba, as good as he was still had that one aspect that he was so good at. And I’m not sure that it’s humanly possible to master every aspect of MA. Oh well, I can try! 
Master of yourself…that is the goal.
Depends on the definition
It depends on the definition you wish to use.
In the classical shaolin period, mastery was considered “life devotion” to a specific shoalin system. Mastery never occurred before the age of 50.
Not all MA’s define mastery in this manner. So it depends on the context of reference.
True, mastery for me means a total and complete perfect grasp on a technique/ system and the ability to execute it flawlessly every time. Which of course is unattainable.
Mastery,..is there such a thing?
I feel that mastery is in itself an abstract concept.
Mastery of what? Or as compared to what?
Many martial arts masters no longer have the physical ability and yet they are still considered masters.
Therefore mastery doesn’t indicate superior skill and ability.
Many masters have had less than 5 students throughout their life, therefore years of teaching do not indicate mastery.
There are those masters who have trained for as little as 10 years and those who have been training for over 70 years.
Therefore time in training is not indicative of mastery.
Some masters are very knowledgeable concerning the science of their arts while others are not. Therefore knowledge is not necessarily a sign of mastery.
So what is?
Wisdom perhaps?
how about a COACH???
There are always deeper levels. My teacher seems like a master compared to me and the other students, and can completely control us even while having a conversation with someone else (well, except for some of the seniors). But then if his 89 yr. old teacher comes to visit from Taiwan (everyone calls him “master”) he’ll totally control my teacher and tell him things like he needs to relax more. I also bet my teacher’s teacher’s teacher could show my teacher’s teacher a few things, too. In terms of mastery, everything is relative.