There are those that spent many years training in the martial arts but that never sought out the deeper aspects of their discipline, style or tradition. One can spend many decades without ever graduating from movement to deeper understanding.
In Kung Fu, each style has deep wisdom that is passed on only to a select few and to those that truly seek more than the outer. This is true Internal training, seeking the deepests aspects of your art, internalizing the art. This internal sphere of knowledge is where the "secrets" lie. A better description than secrets would be proprietary information, knowledge that is reserved for a few that deserve it, earn it and that can preserve and expand it.
This by the way is true of any field of study, discipline, art, science, sport, etc. There are stories of pitchers only passing on their best personal pitch technique to their son, mathematicians working on a problem for decades and giving their research and work to a selected succesor or a craftsman passing on his special skill to an apprentice. The key to this transmission is not just the desire of the student/aprentice/disciple, but also their ability to comprehend the knowledge and their respect for the knowledge received.
There are those that say there aren't any secrets. These are usually the people that never had a peek inside, that have stayed on the outside so long that they can't imagine there is more. Sometimes these people stumble on inner knowledge, but without the correct mindset, and prior preparation, it won't reveal itself to them.
Unfortunately, the sad truth is that years of training sometimes yield arrogance instead of understanding, and what the scholar is blind to is sometimes revelead to a babe (babe = unpretentious, humble, eager to learn, good heart, right intentions, desire to know).
Concentration, Spirit, Aura
Postures, Waist strength, Stances
Hardness can not withstand extreme softness
Softness can not withstand extreme hardness
Nothing is impenetrable
Only speed is impenetrable
Power is at mind (thought)
Internal (jing) comes from “den ten” (dan tien)
