The self-discipline functions either like the rule of a game or like the physical support of a game.
In the first case, the rule allows many transgressions, since the rule is made for a specific game, but it is not an inner part of it. A rule is an intellectual regulation, but the game is essentially a physical item. Therefore, the self-discipline depends on someone’s changeable disposition to take the rule seriously.
In the second case, the self-discipline would be stronger, since it is a part of the game itself. However, because it is far from a clear rule, it is also susceptible to allow transgressions. There is a different type of transgression. It is not simply transgressed a rule, but the disciplined life loses itself in the favor of other forms of living which can be stronger than the discipline.
For instance, we see many people who do not keep the self-discipline in nutrition, though it was deeply assumed. Surely, many legitimately find that the reality of their fat body is stronger than the discipline. Also, we observe how many intellectual or spiritual ideals are abandoned for domestic preoccupations when the people get old. Many of such ideals were deeply assumed by them, but they meet stronger realities, too.
Therefore, to keep a superficial or playful rule comes to be a better recipe for self-discipline. Nonetheless, all the serious goals of life would prove to be only self-imposed and so haphazard rules.