Based on other martial arts I ' ve done , eventual lack of training partners who have the skill set needed to work on what I want to work on . About 10 years into other arts I had developed a very particular interest in what I wanted to make progress with and a very limited group of people with whom I could actually make this progress . I travel around the country several times a year just to have a chance to work with them . 99 % of the time at my home dojos I ' m teaching , drilling basics with beginners , and putting almost all my effort into making them competent at the expense of my own development . The retention rate of new people is so low especially past the 45 year hump when your progress slows immensely and things get frustrating that it ' s a never ending stream of newbies and sometimes it feels like the investment is just not paying off . Hopefully BJJ will continue to grow so that in a decade there are a lot of advanced people around , but I ' ve already seen a lot of brown and black belts just stop showing for class as often as they used to out of boredom .