Lack of self-discipline. Discipline comes through self-control. This means that one must control all negative qualities. Before you can control conditions, you must first control yourself. Self mastery is the hardest job you will ever tackle. If you do not conquer self, you will be conquered by self. You may see at one and the same time both your best friend and your greatest enemy, by stepping in front of a mirror.
Procrastination. This is one of the most common causes of failure. "old man Procrastination" stands within the shadow of every human being waiting his opportunity to spoil one's chances of success. most of us go through life as failures, because we are waiting for the time "to be right" to start doing something worthwhile. Do not wait. The time will never be "just right." Start where you stand, and work with whatever tools you may have at your command, and better tools will be found as you go along.
You will only find pain living in the past.