One who is humble is one who can admit his mistakes. Elder Paisios takes this one step further and says its even better to be aware of our weaknesses.
The one who realizes his mistakes, has already progressed half way. However, it is also very important for him to sense his weaknesses. It is much better to be aware of our own weaknesses, than to struggle very hard, while neglecting it.Why is this so important? Because when we know our weaknesses, then, we have a chance of avoiding our mistakes. For example, if we have a problem with drinking too much, we can stay away from activities that encourage drinking. If we are prone to become argumentative then we can avoid the friends or TV commentators that encourage this. Once we know our weaknesses, we can arrange our life to avoid those situations where our weakness leads us to mistakes.
Reference: Elder Paisios of the Holy Mountain, p 130