كتاب قوة الانضباط الذاتي

If, for example, you can't stick to your study schedule or exercise schedule as you always planned, or you generally have difficulty doing the things you plan, and you have habits such as delaying and procrastinating to the last minute, especially in matters that form a major part of your day; You suffer from "lack of discipline" in your life in general.

Having discipline is not a secondary thing that can be ignored, but rather the most important principle of success, if you have 999 principles of success, none of them will bear fruit if you do not have self-discipline