PLUM PROJECT I first encountered Chin P'ing Mei (or The Plum in the Golden Vase; an anonymously written 16th-century Chinese novel) when I was living with my parents in Nanjing in 1949-1950. I started to translate it in 1982 - and finished in May 2012. The last volume came out in September 2013. I had already been studying the text for more than 20 years before I undertook the translation. I knew the translation would take at least that long. I didn't know whether I would live long enough to do it.

DAYS OF WAR I was born in 1933 in Nanjing. My father (Andrew Tod Roy) was a missionary and a professor in the philosophy department at the University of Nanking. My mother was also a missionary. My parents had been in China since 1930. In 1936, they took me and my brother back to the United States. The Japanese war began in 1937. When we went back to China in the winter of 1938, the University of Nanking had moved to Chengdu, to escape the Japanese. We arrived in Chengdu and lived there until the summer of 1945.

SEEING DEATH Chengdu was quite an impressive place. It had a city wall surrounding it completely. I played on the wall frequently. I liked to play, and sometimes did dangerous things. My brother (J. Stapleton Roy, who, in the 1990s, would become US ambassador to China), who is two years younger, once fell about 15 or 20 feet from the gingko tree in our yard and hurt himself badly. After the Pacific war began, the Japanese were bombing Chengdu several times a week. We built a dugout air-raid shelter in the yard. The Japanese were primarily interested in bombing industrial areas but on one occasion, they dropped bombs on a park which was full of people. Hundreds were killed. After that air raid, I walked out with my parents to see what had happened. That was the first time I saw dismembered bodies lying around. They had brains oozing out their skulls. That was a very sombre experience, to say the least. I was terrified.

SAFETY IN HONG KONG After the Korean war began, in 1950, my parents decided they would still try to stay on. But since my brother and I would soon be going to college, they decided to send us home. The Chinese government decided to get most if not all the remaining foreigners out of China. They chose to have public attacks on the most prominent Western faculty members at all 13 Protestant universities in China, including the University of Nanking. My father was singled out for the attacks. My parents went to Hong Kong in the mid-1950s. My father taught at the Chinese University. They remained in Hong Kong until they retired, in 1972.

SEX EDUCATION As a teenage boy, I was attracted by Chin P'ing Mei's reputation of being pornographic … but when I tried to read it I discovered there was much more to it than that. I studied Chinese history and literature both as an undergraduate and graduate student at Harvard University. And I taught for four years at Princeton University. While I was at Princeton, I taught an abridged English translation of the Chin P'ing Mei. I became more and more fascinated by it and convinced that its reputation as a work of pornography was misleading. It describes the clothing women wear, the food people eat, the varieties of corruption in which they engaged and the way in which the legal system was misused by people with bureaucratic power. There is no more attention paid to sexual activity than there is to other daily activities.

When I moved to the University of Chicago, in 1967, I was offered the opportunity to teach a seminar on any subject of my choice. I decided to teach a seminar on the Chinese version of the Chin P'ing Mei. I only had one student. His parents were Lutheran missionaries in China. He had also grown up in China, so the two of us read through the entire 3,000 pages or so of the earliest edition of Chin P'ing Mei. It took us two years. I became aware of the fact that this novel was also unusual in that it contains so much material quoted from earlier works. But the sources were not identified. I spent several years indexing every line of poetry and proverbial sayings and dramatic quotations, etc. I filled out more than 10,000 three-by-eight file cards. After that, I set out to try to read all the earlier works that were in print before the novel was compiled. I was able to identify thousands of sources that had not been identified before in scholarship on the novel.

MAKING A CALL Computers were just coming into general use at the time, in 1982, when I started the translation. My wife persuaded me to get a computer. Now I am still using the computer I bought in 2000. I spend only about 10 or 15 minutes a day online. I don't even have a cellphone. I cannot be bothered with it. It annoys me when I ride the bus between my office and my home and see most of the students of the University of Chicago sitting there fooling with their cellphones.

NEW CHINA When my wife and I went back to China in 1993, when my brother was the US ambassador in Beijing … the difference from the China I remembered from my childhood was really noticeable. In any direction you saw construction going on. I've never liked what seems to me to be the totalitarian aspect of the Chinese government. I am extremely critical of the government for that, but I also recognise they have done a great deal to improve the physical environment for Chinese people. Also, literacy has been enormously improved.

LIFE'S WORK I was diagnosed with ALS (often known as Lou Gehrig's disease) when I finished the translation. I am losing control of my fingers so I can no longer touch and type. It's getting more difficult to eat because I have difficulty manipulating the knives and forks. Every day I am getting weaker. I no longer have the energy to want to do anything. I do miss the focus I had on the translation. I've always enjoyed my work. I've never wanted to do anything else.