What do you mean by "those self-draining, rich in mud, but not me"?

Moral: He stays away from muddy water alone, like a cicada, floating in the world, not humiliated by the turbid world, keeping the quality of light and producing sludge without being stained.

Original sentence: cicada sloughs in mud, except floating dust, it is not loved by the world, and it is also mud instead of me.

Origin: Biography of Qu Yuan is an excerpt from Biography of Qu Yuan in Historical Records, and it is a biography with unique style. This is the earliest complete historical data about Qu Yuan and an important basis for studying Qu Yuan's life.

Qu Yuan (about 340 BC or 339-278 BC) was a poet and politician of Chu State during the Warring States Period in China. Born in Chu Danyang (now Xichuan, Nanyang, Henan). Mi surname, Qu family, human, the word is native; Since the cloud name is regular, the spirit word is even. The descendants of Qu Xian, the son of Xiong Tong in Chu Wuwang during the Warring States Period. When I was a teenager, I was well educated, knowledgeable and ambitious. In his early years, he was trusted by Chu Huaiwang as Zuotu, and was also a doctor of San Lv, in charge of internal affairs and foreign affairs. He advocated "American politics", promoting and appointing talents internally, perfecting statutes and uniting external forces to resist Qin. Slashed by nobles, he was exiled to Hanbei and Yuanxiang Valley. After General Qin attacked Ying, the capital of Chu State (now Jiangling, Hubei Province), Qu Yuan drowned in the Miluo River and died heroically.