The martial arts are based upon understanding, hard work and a total comprehension of skills. Power training and the use of force are easy, but total comprehension of all of the skills of the martial arts is very difficult to achieve.
A lot of people change for good. Some people just fall off. Just trying to progress in anything, no matter what you're doing, I feel like any progression you make... some people aren't gonna be around you that were around you.
You have to have the service mentality in the sense that you subjugate your own ego, and you subjugate a large part of your own life to really helping other people, being successful on their behalf.