Originally, there were 24 patterns in Tae Kwon Do. This reason for this was explained by General Choi (founder of the present day Taekwon-Do) as:
The life of a human being, perhaps 100 years, can be considered as a day when compared with eternity. Therefore, we, mortals, are no more than simple travelers who pass by the eternal years of an eon in a day. It is evident that no one can live more than a limited amount of time. Nevertheless, most people foolishly enslave themselves to materialism as if they could live for thousands of years. And some people strive to bequeath a good spiritual legacy for coming generations – this way, they gain immortality. Obviously the spirit is perpetual while material is not. Therefore, what we can do to leave behind something for the welfare of mankind is, perhaps, the most important thing in our lives. Here I leave Tae Kwon Do for mankind as a trace of a man of the late 20th Century. The 24 patterns represent 24 hours, one day, or all my life.