The brilliant author of "A stroke of Insight" and harvard's own "Brain Banker", Jill Bolte Taylor, has found through studying the human brain that it takes "less than 90 seconds for an emotion to get triggered, surge chemically through the blood stream, then get flushed out".
What does that mean in spiritual terms? It means that the days, months and sometimes years that we spend blaming someone for our own state is a complete hoax.
How then is it that we remain angry, disappointed, frustrated and hurt by someone else's actions for way, way longer than 90 seconds? Well, the painful and short answer is: we do it ourselves. Through the replaying of events, attaching past experiences that seem similar and building up many scenarios of victimization, blame, revenge and fantasies about re-doing the past or fixing the future we re-live those stories in our heads over and over and over again. This in turn internally re-creates the trigger and response cycles.
We jail ourselves into this torturous internal storytelling causing ourselves our own suffering. Many of us resist this idea as it gives us full power and control over our own mental and emotional state and yet once you accept it, there's nothing more liberating.
"How people treat you is their Karma, how you react is yours".