Doubt

Doubt is an uncertain feeling or lack of self-assurance. We are often our own worst enemies and set up our own failure by doubting our own abilities. Doubt causes us to be unsure in the face of our challenges, the exact time when we need self-assurance. Doubt can arise for several reasons.

Past failures. As stated before, everyone has failed and will fail at different points in their lives.
False guilt. You feel incapable and are overly hard on yourself.
Negative influences. These may come from your environment or from the people with which you interact. You must change your environment and circle of friends.
Poor self-image. We are the way we think we are. If you have a poor self-image, you need to start believing in yourself and realize that you are ultimately responsible for your own self-image.

Many delay testing for rank advancement because they doubt their ability, even when reassured by their instructors. Remember, if you have done a technique correctly once, you can do it again.

Making Excuses

When you are looking for an excuse, any excuse will do. Some people are experts at making excuses. They have a different excuse for everything that goes wrong. Unfortunately, excuses build into your character the qualities that will ultimately lead to your defeat. You must change your attitude, stop wasting time and energy on excuses, and channel that energy into achieving success.

Ask a non-trophy winner how the tournament was and you will hear a million things wrong with the tournament. if you ask a trophy winner about the same tournament, you will hear about how great it was. No one wants to hear excuses.

Procrastination

Procrastination can be defined two ways: putting off until tomorrow what you should do today or putting off until tomorrow that which is discomforting for you to do today. Procrastination can also come in the form of perfectionism. A perfectionist may be so bogged down by worry that he or she will be unable to achieve a high level of perfection that he or she will delay ever starting. Our goal in Taekwondo is to reach perfection of technique; however, we know that perfection is unattainable, so not attaining it is not considered a failure. Failure is merely a bump on the road to success. So stop worrying about being perfect, relax, and get moving.