Echoes from a distance

Shortly after I had returned from a foreign trip some years ago, an old friend saw me and quickly noticed that I had gone partially bald. He was startled. So, he spontaneously yelled a seemingly tough question at me: ?What happened to the hairs on your head?? Spontaneously too, I yelled an answer back at him: ?Nature took them in place of the wisdom that I couldn?t pay for!? And we teased and laughed. My friend thought I had joked, but I knew I hadn?t. However, I?ll leave the judgment to you. By the time you?re done digesting the substance of this more than compelling masterpiece, I?d like to know your stand. Had I joked or had I not?