Robert K. Massie said this quote

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.

~ Robert K. Massie

She (historian Barbara Tuchman) draws on skepticism, not cynicism, leaving the reader not so much outraged by human ability as amused and saddened by human folly.

~ Robert K. Massie

Books were her refuge. Having set herself to learn the Russian language, she read every Russian book she could find. But French was the language she preferred, and she read French books indiscriminately, picking up whatever her ladies-in-waiting happened to be reading. She always kept a book in her room and carried another in her pocket.

~ Robert K. Massie

In January in Northern Russia, everything vanishes beneath a deep blanket of whiteness. Rivers, fields, trees, roads, and houses disappear, and the landscape becomes a white sea of mounds and hollows. On days when the sky is gray, it is hard to see where earth merges with air. On brilliant days when the sky is a rich blue, the sunlight is blinding, as if millions of diamonds were scattered on the snow, refracting light. In Catherine's time, the log roads of summer were covered with a smooth coating of snow and ice that enabled the sledges to glide smoothly at startling speeds; on some days, her procession covered a hundred miles.

~ Robert K. Massie