Holding onto things that bother you, or even worse, really piss you off, is a form of attachment. And when one clings onto something and forms an attachment with it, the possibility for suffering arises. For one is never happy or content, That’s because with attachment, comes the desire for more and the fear of loss of what you have. “I want that thing badly; can’t live without it. Oh my god, what would I do without it?”
Besides only gaining suffering, one also looses something with attachment. And that is your mind, or rather your peace of mind. Contentment and well being flee when a bad case of attachment hits. When I got totally pissed at someone recently, I couldn’t let anger go. I was wronged. I was the victim, and not the bad guy as accused. But instead of feeling any the better for it, I felt bad; both physically and emotionally. I was up-tight, frustrated, everything turned to shit with endless re-runs of how I was wronged running through my mind. There was little room for anything else. Damn, instead of grasping on to all this anger, I should have been fleeing from it. Running for my life. Cutting it loose.