During one of his tours to U.S.A., Swami Vivekananda was watching some boys standing on the bridge & shooting eggshells floating on river. They failed almost at every try and Swami could not help but smiled. The boys were annoyed and passed a remark; it is not as easy as you think it is. Swami took the gun from one of the boys & fired at 12 eggshells without missing a shot. Boys were left amazed at his skills & asked him how he did it.
Swami ji who held the gun for the first time in his life replied, whatever you are doing put your whole mind on it. If you are shooting your whole mind shall be at the target. Then you will never miss. If you are learning any new lesson or skill put your whole focus. In my country, boys are taught to do this.