Past hurts, traumas, insults, bitterness, etc., harden us. We can let God deliver us and turn experience into a victory that ministers healing to others, or we can set in our hardened condition and use our past as excuse for being bitter, angry, hardened, untrusting, etc.. Our past can enslave us or we can walk free.
It may not be easy: bringing the ugly to the surface where it can be properly dealt with can hurt for a bit. It can take time as God works here a little, there a little to free us up. But the pain caused by the work of healing is better than sitting in our hardened state, becoming harder, and bringing others with us into a state of hard heartedness as we hurt them.