A life long journey...
It's never enough. Whatever the reason that brings you to the Martial arts, there is no point, no marker, no level of skill or ability that you can achieve then stop, and still enjoy the benefits that the Martial arts gave you.
If you studied martial arts for physical fitness, and reached the peak of physical health and stopped. You would loose the strength and flexibility that you had attained through practice, and you would become flabby and weak again.
If you studied martial arts for self defense, then it is impossible to reach a level of skill that could guaranty success and the safety of yourself and your loved ones in any situation. So you much ever strive to be better and get closer to that unattainable goal. Even if such a mythical level of skill where attainable it would take persistent effort to maintain that level of skill. As it does any level of skill.
If you studied martial arts for the honor and prestige of being a “black belt”, then you are nothing less than a fool, because once you have reached that point there is a even longer journey ahead of you. It is then that you have just attained enough basic skill to begin your REAL training.
“All human skills are perishable. Just like fruit. You leave 'em on the shelf too long, they rot, they decay, they stink.” - Sara Pezzini (Witchblade)