if I had been willing to accept that peoples past behavior was a strong predictor of their future, I could have saved myself much self-induced grief, caused by people failing to live up to the potential I thought they had. I knew who they were, but thought they'd transcend it.
I've recently had this lesson rubbed into my face in a rather undeniable & painful way, and have begrudgingly been forced to accept it. I don't really know where I'll go from here, considering how much of my worldview is upended by the loss of this axiom; people are who they are.