The Adventures of Xiaobutou. [Photo provided to chinadaily.com.cn]

Two years later, he left the army and returned to high school. In 1954, he enrolled into Beijing Russian Language College (later part of Beijing Foreign Studies University) and one year later, he transferred to the Chinese department of Peking University. Sun went to teach at Beijing Foreign Affairs University in 1960.

According to members of Sun's family, he used to exchange his food and clothes for books in his early youth. Since a young age, he started building his own library and lent books out for free for years. He also learned Japanese and Russian and translated seven fairy-tale titles in the two languages.

Over the years, Sun not only won millions of readers, but also various kinds of awards, including National Excellent Prize for Children's Literature and Soong Chingling Children's Literature Prize. In September 1990, Sun went to deliver a speech at a conference organized by International Board on Books for Young People as a nominee for Hans Christian Anderson Award.

Keeping a diary every day, he wrote down more than 20 million words throughout his life, leaving a rich literary resources behind.

A bookworm, a good storyteller, a genius, and a man passionate about life, Sun was a modest "Strange Old Man", as his fans, fellow writers, friends and family call him affectionately.