As writers, we are told not to present perfect characters.
Those inhabiting our story must possess flaws, hang-ups, imperfections, and internal conflicts.
Sometimes it is difficult to assign these negative characteristics. We love our characters and don't want them to be too unlikable, ignorant, or emotionally unstable. Our readers must identify with these people and root for the heroes. What if we go too far and create a character too offensive or pathetic?
The secret is to have our characters outgrow some of these negative issues.
Remember the ugly duckling. Homely as a chick, he eventually grew into a beautiful swan.
Our characters can grow and change as well. During the course of our story, situations will arise that challenge our characters, forcing them to improve and adapt. The basic storyline will likely involve the overcoming of poor behaviors, mental fears, or emotional barriers. The bully will cease to fight. The antagonist will realize the error of his ways. The wallflower will understand that she can achieve more. Some characters will remain stuck in their ways (and some will even regress) but others will flourish and grow.
And by the end of our story, while far from perfect, they will resemble a beautiful swan.