To prove to [her friend, Swedish diplomat Count] Gyllenborg that she was not superficial, Catherine composed an essay about herself, "so that he would see whether I knew myself or not." The next day, she wrote and handed to Gyllenborg an essay titled 'Portrait of a Fifteen-Year-Old Philosopher.' He was impressed and returned it with a dozen pages of comments, mostly favorable. "I read his remarks again and again, many times [Catherine later recalled in her memoirs]. I impressed them on my consciousness and resolved to follow his advice. In addition, there was something else surprising: one day, while conversing with me, he allowed the following sentence to slip out: 'What a pity that you will marry! I wanted to find out what he meant, but he would not tell me.