In 2003, I had been sharing tender, vulnerable things about to myself to critical people. Bart Anderson, the spiritual teacher that I was working with shocked me one day. He said, "They don't deserve your heart." This seemed to go against everything that I had learned from him. He continued (and I paraphrase), "Well, look at it. You and the people you are sharing with are coming from two totally different places. You are opening your heart and being vulnerable, and they are criticizing you and using it against you. Why would you do that?" I didn't have a good answer. But I did stop doing it. He called it "discernment."
Years later I recognized a similar pattern sharing vulnerable things with careless people. And, investing lots of energy in them. It was not working out well. I was getting hurt. This is when I remembered the Foolish Heart song. I stopped doing that, too.
I still allow myself to be vulnerable, but I am much more selective with whom I share sensitive things with these days. But every now and then, I forget and pay the price. That's about when I hear Jerry Garcia's voice singing, "...Unto a foolish heart."