During the late Western Han Dynasty, Wang Yu, son of the powerful official Wang Mang, was concerned about his father's actions creating numerous enemies. He bravely offered a remonstrance, but Wang Mang, prioritizing his perceived duty over family ties, had him executed.

Observing this, Feng Meng understood Wang Mang's true nature and concluded that such a ruler was unworthy of loyalty. Consequently, he took off his official's cap, hung it outside the East Gate of the capital, and quietly departed the city, taking his family to Liaodong.

Not long after, Wang Mang committed suicide, leading to the collapse of his Xin Dynasty.