My simple offering is that we need impulse control to be successful, but we also need spontaneity. Teachers and students alike can find themselves mourning a loss of wildness, begrudgingly exchanged for the ability to focus, concentrate and persist.
Martial arts are often rightly credited with the ability to instill discipline in the unruly youth-- to curb desires and focus passions-- to turn libertines into responsible citizens.
I myself have often been sited for my patience and my self-disciplined example. Yet, I'm prone to identifying with the indolent prince, the artful dodger, and the easy life.
Daoism, despite its intricacies and difficult methods, has been called an apophatic tradition. Which means it teaches by unteaching, it reveals by showing what is not so, rather than what is so.
So, with Taijiquan (and other internal arts) it is said that all movement initiates from the dantian (the belly region?). To actual do this requires extraordinary impulse control. Why? Because impulses are how we initiate movement. Any impulse which originates in another part of the body will impede the one true impulse from the dantian.
One might even say that tension itself is a rouge impulse stuck in the "on" position. This is usually stated in the positive: "relax," "let go," "melt." But the actual "doing" is "not doing." This "not doing" takes years to undevelop, and comes with a simple guarantee; you can only get as much as you are willing to give up.
In the end all good teachers transmit the idea that the worthwhile result of impulse control is freedom itself.
So people sometimes ask me, "What does qi feel like?" It can be understood as an anti-feeling, a sensation of constant, unbroken, impulse control.