Zuo's concept of being an official has always been that if you want to be an official, you must do your best. If you want to be an official, you must be a good official who serves the people. In the historical situation of Qing dynasty, if you want to make a difference, you must be a high-ranking official. Therefore, Zuo believes that the position of county magistrate still cannot display his ambition. Therefore, he would rather go home to farm than be a magistrate. He would rather hide his strength than be a superficial local official there.
The reason why Zuo has never been a big official is actually very simple, that is, his education is not enough. He is only a juren, and juren is one level less than the ancient Jinshi, and the worst Jinshi is the magistrate of a county. Zuo is not even a Jinshi. He is only a juren, but he doesn't want to be a pen. So he didn't choose to be an official and stayed at home for a long time.
However, due to his academic qualifications, even if he worked well under others, it was difficult to be promoted to a high position, which led him to always think that he was a talent, and we can also see how strict the official selection system was in the Qing Dynasty.