I have had many conversations with people about how to cultivate self-discipline. Self-discipline is exercised in a moment of choice. Lack of self-discipline is the ego always following the desire of the moment. Alternatively, sometimes a loss of discipline happens when raw emotion overwhelms us. Fear and anger can drive us to take self-destructive actions. In the critical moment of choice, you will be faced with whether you will give in to it or not.
Excerpt from Chapter 27, Sovereignty – The Tao Principle of Self-Management