Confucius, known as Kong Qiu, styled Zhongni, was a thinker, statesman, and educator of the late Spring and Autumn period, and the founder of Confucianism.
When Confucius was growing old, he began traveling through the various states. At the age of 64, he arrived at Ye Yi in the state of Chu, near present-day Ye County in Henan.
When Shen Zhuliang, the magistrate of Ye County—known as Lord She—warmly hosted Confucius, he had only heard of Confucius as a famous thinker and politician who taught many excellent students but knew little about the man himself, so he asked Confucius’s disciple Zilu, "What kind of person is your teacher?"
Zilu had studied under Confucius for many years, yet when asked a question he could not answer, he simply remained silent.
Later, Confucius learned of this and said to Zilu, "Why didn't you answer him like this: 'As for Confucius as a person, he studies tirelessly, even forgetting to eat; he delights in teaching and spreading the Way, never worrying about poverty or hardship; he strives unceasingly, even forgetting his own age.'"
Confucius' words reveal that, driven by a lofty vision and relentless effort, he lived a profoundly fulfilling life.
The idiom "to forget sleep and food" means being so absorbed in something that one neglects sleep and meals, describing dedicated work or study.
Source: *The Analects*, Chapter "Shu Er"
Meaning of the Idiom: Later, the Chinese idiom "废寝忘食" came to describe being so absorbed in something that one neglects sleep and meals, describing dedicated work or study.