This article is adapted from the author’s forthcoming book, The Defiant Optimist. “Bahu!” my friend Radhika called out from a distance. Central Park was bursting with flowers and kids running around when I found a bench under the shade of a tree to rest. I was supposed to meet Radhika here to catch up. And we had so much to catch up about. Since our days at Smith, Radhika had become an embodiment of the Lower East Side. Free-spirited, creative, and optimistic, she was writing a book about how jazz musicians create music. Rob and I had been back in…