In the mid 80's and throughout the 90's, I was fortunate enough to train with some really great JKD guys (which was my eventual introduction to bjj-my home). It started with a really progressive karate guy that I trained under, John Rhodes, who was "radical" at the time by incorporating Wing Chun, Aikijujutsu, and JKD into his curriculum. Then at college, I trained with Steve Woodward, Frank Cucci and was introduced to Larry Hartsell, eventually then Erik Paulson. Although I am primarily a grappler, I realize that combat happens outside the grappling range and the martial artist needs to be prepared for it all. I just watched this documentary and it is a really great piece on JKD.
It should be noted also that in this documentary, Dan (an original student of Bruce Lee)is in his 70's and moving quite well. I was informed by a great trainer friend of mine, Tom Furman (go to his site and get trained by him or even purchase his ebooks or dvd's- they will transform you), that Dan along with Bill DeThoaurs and Dr. Harold Koning (both silat) are 76 and still training every day. Dan did not start training bjj (he is now a black belt under the Machado's) until he was in his 60's. Renato Pacquet is 79 and still grappling every day. It is the Blue Zones principle...find out what they are doing and do it. Aging gracefully. This is great wisdom for me and I turn 45 tomorrow and feel like I am just starting out. We may not be able to stop the hands of time, but we can make them move more slowly.