Its common knowledge that Bruce Lee is the founder of JKD. Before creating JKD Bruce Lee had trained in multiple styles most notably Wing Chun but there are stories about many of the other styles he trained in. There was one case where he made a deal with an instructor. This particular instructor taught some style of kung fu although Im not sure exactly what kind. Anyway, Bruce Lee, aside from training in the martial arts, also was really good in cha cha dancing. He made a deal with this instructor that in exchange for some lessons in the kung fu that he taught, Bruce would teach him cha cha. According to the instructor it would take the average person about three months to learn the basics of his kung fu. It took Bruce Lee three days to master the basics. So much for his cha cha lessons, the instructor said, three days was just enough for him to get down the basic rhythm. Anyway the point is if you're phenomenal like Bruce Lee you can reach certain levels much faster than the average person. No, martial arts can't be rushed, if by rushing you're skipping over certain stuff, but it is possible to learn it faster depending on how much you put into it. Bruce Lee would disagree with people who say you can't progress faster.