Once a kata has been learned, it must be practised repeatedly until it can be applied in an emergency, for knowledge of just the sequence of a kata in karate is useless.
Gichin FunakoshiIt is important that karate can be practiced by the young and old, men and women alike. That is, since there is no need for a special training place, equipment, or an opponent, a flexibility in training is provided such that the physically and spiritually weak individual can develop his body and mind so gradually and naturally that he himself may not even realize his own great progress.
Gichin Funakoshi