An incident occurs, but at the time its gravity of meaning is not realized. Many incidents occur over time that are of that nature. They remain in your mind, your memory of them occurring time and time again. It may take years for the gravity of those incidents to gel and develop into hatred.
You may struggle to relieve the thoughts, might even make a valiant effort to make them fade into obscurity. A mind does not work that way. Though time may lessen the hurt the thoughts recur again and again. Some thoughts flare into the mind with an intensity equal or surpassing the levels experienced when they occurred.
Finally, you realize the depths to which the incidents affect you. You are able to point at the specific moment when an incident became overwhelmingly disturbing, affecting your relationship with the author of the words or actions remembered. You begin to realize the emotion the memory produces is hate. From that moment on the relationship is changed. You may have been close, but now the distance between becomes insurmountable. You just don’t know them anymore. They become like a stranger. A stranger that you feel animosity towards. You desire they just stay away. In some cases, you’d rather never see them again. Yet the memories remain. Then you are eternally faced with the desire to make the memories go away.