Always learn to appreciate everyone that walks into your life. People come into your life for various reasons. All those reasons make part or whole of your life.
Probably, some people have hurt you so much until you regretted why you allowed them into your life and affairs. I may not fully understand your case. That’s alright but remember that such people come into our lives to teach us lessons. We need to appreciate all that happened until they left. Thank goodness it happened. So take the lesson not the grudge.
On the flip side, others come into our lives to change it for good. They make us realize our potential….and almost certainly, our destiny had not been fulfilled until they came. Thank goodness they came.
Whether good or bad people walked into your life, it doesn’t matter so much as to how you reacted or took the situation. A mature person is the one who can still appreciate both the bad and good people even after going through a bad experience.