Wen loves reading books, especially classic works, the memoir revealed. One of his favorite Chinese writers is Lu Xun, a leading figure of modern Chinese literature, and he wrote that he had read Call to Arms three or four times.

In addition to reading, Wen spent much of his spare time running. In two of his working notes in the book, Wen records getting up at 5:30 am to run, a routine that was not even interrupted on weekends.

He also had a determination to learn English. In a diary entry from April 1981, Wen said he would study hard and aim to speak and understand English reasonably well before the age of 45.

The memoir offers a rare insight into the historical changes in China's geological sector and its achievements in the early period of the country's reform and opening-up.

In a recent interview with China News Service, an editor from Geology Press said Wen sent many of his diaries and notes to the press in March 2014, adding that the former premier wanted to publish the book to express his feelings of nostalgia for the past.

Wen sent 15 letters amending the manuscript and also participated in designing the book's cover, according to the editor who remains anonymous.