In 1835, Marx in the middle school wrote his understanding of the happy era in a composition, that is, "the fashion is simple, aggressive, and the officials and people are impartial.". At the same time, he pointed out that if an era "is full of greed, luxury and indulgence, then this era cannot be called a happy era". Marx's life is a life in which he bravely climbed the ideological peak in pursuit of truth without fear of difficulties and dangers. He selflessly funded the revolutionary cause, often pawned clothes to buy manuscript paper, and sold his wife's dowry to run the New Rhine Newspaper. In Marx's opinion, appearance decoration is irrelevant, while internal cultivation is important. He said, "It is better to arm himself with knowledge than to decorate himself with gorgeous clothes." In 1858, when the Criticism of Political Economy was finalized, Marx had no money to send it to Berlin for publication, so he had to ask Engels for help. In this regard, Marx sighed: "It is unlikely that anyone will write about money in such a situation of lack of money." In fact, Marx was not unable to get rid of poverty. The Prussian government had offered to find him many times and offered him decent work and generous remuneration, but he refused. In 1846, in a letter to Carl William Leskay, the publisher, he expressed his determination: "For the sake of the work itself, I would never hesitate to bear the economic losses." In 1859, in a letter to his good friend Joseph Weidmai, He once again firmly said: "I must go to my goal at any cost and not allow the bourgeois society to turn me into a money making machine." Although Engels was born in a rich family, he shared weal and woe with the working class all his life. In order to write The Situation of the British Working Class, Engels spent two years to investigate the poorest neighborhoods in Britain. In 1845, he dedicated this book to the British working class and wrote in his letter: "I abandoned social activities and banquets, the bourgeois Portuguese red wine and champagne, and spent almost all my free time interacting with ordinary workers. I feel happy and proud of this." In his view, in addition to food, clothing and shelter, there should be higher pursuit, As he said, "The highest state of life is to make a difference". Lenin cherished lofty ideals and never pursued personal life enjoyment. Before the victory of the October Revolution in Russia, he lived in a straw shed and ate black bread and cabbage soup like the workers. After the victory of the October Revolution, he was still frugal and had no extravagant demands on life. Someone wanted to give him a new coat. He said seriously: "We have won, but we still have to use more money for domestic construction, expand our production, and arm our troops!" He shouted loudly: "Everything is for the happiness of the Soviet people, not just for personal enjoyment." In 1922, at the Fourth Congress of the Communist International, Lenin made a clear request to the state organs: "In any case, we must streamline our state organs, and we must save as much as possible." From Marx and Engels to Lenin, the proletarian revolutionary instructors have set an example of hard work and plain living. Always keep hardworking and plain