The Foolish Old Man of the fable 愚公移山 in the book 列子: at ninety he starts digging away two mountains, saying his descendants will carry on. 毛泽东 made the story a byword for perseverance.
The story of Yu Gong moving the mountains is known to everyone.
Tips
history
The tale is in the 汤问 chapter of the Liezi. Mao's 1945 speech of the same name closed the Party's Seventh Congress and became one of the 老三篇, the three short essays pupils had to learn by heart early in the Cultural Revolution.
memory
愚 = 'foolish', 公 = 'old man/sir'. The 'foolishness' is the point - the story argues stubborn faith outperforms the 'smart' neighbor who mocks him.