Before I get into these "5 traits" we kind of need to decide what it means to be a "successful" martial artist. How does one define success in the martial arts? Is it attaining black belt? Is it winning lots of matches and becoming a champion of some sort? Is it getting in really good shape, i.e. becoming strong and fit? Is it optimizing your health? Is it having the confidence that you can defend yourself in almost any scenario? Is it the ability to teach and successfully help others? Is it influencing the community for the better? For the youthful student, is it getting good grades and eventually acceptance into a good college? Is it making friends and feeling connected to other like-minded individuals in an other wise isolative society?
The reality is I can't answer that question for you. Yes, in part, you do need to define what the martial arts are and what it means to be a "successful" martial artists based upon the requirements of your school and your instructors. (This is more than just the curriculum). However, you also need to reflect and determine how the martial arts fits into your life.
For example, for the 20 year old collegian on the tournament circuit, being successful IS WINNING on the tournament circuit. Conversely, to the 45 year old professional, collecting medals might not make much sense but having the self-confidence and sparring and self-defense training creates probably does.
In fact the 20 year old collegian and the 45 year old professional may be the same person.
How you define success as a trainee of martial arts depends upon where you are currently in your life. And, that will change over time.
However you define success, I think these traits are common:
1. Intrinsically Motivated
When most start an endeavor like martial arts or physical fitness the motivators are often external: Losing weight, learning a new skill, building muscle, winning medals, attaining the black belt, etc... However, after a relatively short period of time most, if not all, of one's initial goals have been realized so why keep going? There will be points of frustration: time pressure from others and other activities, diminishing returns, plateaus and perhaps even regressions. How do you keep going? You have to learn to / let yourself enjoy the plateaus and the motivation to do that can only come from the inside. That is not to say that we are not seeking progress, but progress is an external motivator. When you can find the motivation to train and practice for the sake of training and practice alone you will be closer to success as it will enable to persevere through the hard times and reap the benefit in the long term.
The beauty of martial arts training is that it can be done almost anywhere, with very little space and almost no equipment. And, we live in an age of information. The attitude towards martial arts information has really changed over the last 3 decades. When I first started learning and training to become an instructor we had to memorize everything. In fact, Grandmaster Goh did not let me take notes, video or write anything down. All the material had to be memorized. Over time, the outlook changed. We started writing down and recording everything we could. Additionally, there are so many publications, videos and internet resources on the martial arts. There is no shortage of information. Perhaps there is too much information. Make sure you are discerning and skeptical of the resources and information that you procure.
3. Passionate (willing to sacrifice)
First, an interesting etymological point. Passion has the greek passios as its root. Passios means "to suffer". Consider that the next time you say your are "passionate" about something. Are you passionate or just enthusiastic? Do you understand the difference between passion and love? Willing to suffer may be a bit severe, but willing to sacrifice seems right. With that construction we can make an example like this: I'm passionate about my work because of my love for martial arts.
4. Innovative / creative / non dogmatic
One thing I've noticed over the years is once martial artists that attain a rank like 1st or 2nd degree black belt they become set in their ways and even dogmatic about training. There are right and wrong ways of doing things, but don't get stuck in "this is the only way" thinking. Sometimes another way of looking at things is the best way to make your way even better. It's important to remember that once you learn a little you think you know a lot, but soon you learn a little more and you realize you know a lot less then you ever thought.
5. Team player / collaborative
Martial Arts is an individual pursuit through and through. Only the individual can do the work, put the time in, make the effort and absorb the lessons. But, it is also important to realize that no one is in a vacuum. We have training partners and we are part of a training community. That community is interconnected and inter-reliant. Sometimes you will need the help of others and you need to feel that it is OK to ask for help. Similarly, others will often need you to help and it's important that those others know and feel that it is OK from them to ask you for help. There is also a certain synergy and energy to gained from training with a group. It is also strongly tied to point #4. Being collaborative will also help you be more innovative and creative in your training.