Have no rigid system in you, and you'll be flexible to change with the ever changing.
The truth is outside of all fixed patterns.
A good martial artist does not become tense, but ready.
Running water never grows stale.
Defeat is a state of mind; no one is ever defeated until defeat has been accepted as a reality.
Put every great teacher in a room, and they'd agree about everything, but put their disciples in there and they'd argue about everything.