This story originates from The Historical Records. The idiom "the latecomers surpass the old-timers" is now used to indicate that successors can excel their predecessors, which differs from its original context when Ji An used the phrase.
Ji An lived during the reign of Emperor Wu of the Western Han Dynasty (206 B.C.–A.D. 24). He was respected for his integrity, fairness, and outspokenness. Pragmatic and effective, he governed his prefecture with such order that the imperial court promoted him to a central position overseeing the appointment and dismissal of local officials.
Once, Emperor Wu declared his intention to implement Confucian policies of benevolence and justice for the people's welfare. Before the emperor finished speaking, Ji An interjected that such pronouncements were unnecessary. He bluntly questioned why the emperor would pretend to uphold benevolence while being inwardly greedy and avaricious. Stunned, Emperor Wu abruptly ended the audience. The court officials feared for Ji An's safety, but the emperor later merely remarked that Ji An was rather blunt and straightforward.
Consequently, Ji An was never promoted again. While he remained in his post, his junior colleagues Gongsun Hong and Zhang Tang were continuously promoted, eventually becoming Prime Minister and Imperial Censor, respectively. One day, Ji An remarked to Emperor Wu that the emperor's use of ministers was like piling firewood—the later arrivals end up on top. Emperor Wu, recognizing the complaint, turned to his ministers and said, "Indeed, one must never stop learning. Look, Ji An's remarks grow increasingly indiscreet."