If you are doing something to just obtain a result you are really not doing it; that is why in
karate there is never a rush to get the next belt. There has to be substance behind the form and that takes time through repetition, refinement, and application of the techniques.
Many can learn to get the kata pattern quickly, but learning when to go hard or soft in pace and breathing takes time as each kata has its own rhythm and strategy. The kata of karate is a self realization process where one develops their imagination and skill to see the 'opponent' and deal with the different
scenarios that can arise in a real self-defense situation. It is through strong preparation in training that one develops confidence and through perfection of technique that one develops courage. Enhancing one's skill through the process by training daily so that it becomes natural to you so that it is there when you need it is the goal. The whole point of the grading is to test if you know what you think you know that way there are no illusions or delusions in the real situations of what once can or cannot do. To be sure, it never hurts but only helps, to spend the extra time training at each belt level.
This is vitally important in a child's growth.