In fact to do Kung Fu at all, you must be completely present and engaged in what you are doing. For if you are not, then, you will be unable to grasp the complexity or the necessary coordination to output what you are learning.
Examples of this can be seen through all of the stages of learning a martial art. From beginner kung fu students right up to the most experienced martial arts practitioners each student has a challenge of mind and body engagement, that, although different in nature still demands the complete engagement of mind and body into one harmonious team.