To say it never happened,in the sense when someone has caused you pain, is forgiveness in my opinion.
When the hurt stays alive in the memory, it will come back to you sooner or later. Exemple: During a discussion between two people the old hurt ones done and not forgotten can surface again. Fear also plays a role in this, and is very negative. The fear of being betrayed again.Trust being the positive way out.
Easier said than done.