According to legend, Confucius, the great scholar of the Spring and Autumn Period, had over 3,000 students, among whom 72 achieved remarkable success, including the intelligent and diligent Yan Yuan.
One day, Yan Hui approached Confucius, bowed deeply, and said, "Master, when you walk slowly, I walk slowly; when you walk briskly, I walk briskly; when you run, I run; but when you race ahead, the dust from your steps hides your tracks, and I can only stand and stare, unable to keep up."
Confucius looked at his beloved disciple for a moment and asked, "What exactly do you want to ask?"
Yan Yuan explained, "Master, when you walk, I walk; when you speak, I speak; when you move forward, I move forward; when you reason, I reason; when you race ahead, I race ahead; when you teach, I teach. But when you run so fast that you vanish in a cloud of dust, I can only stand there staring. You win everyone's trust without saying much, you bond with people without constant chatter, you hold no power or throne, yet all under heaven flock to you. I truly don't understand how you do it."
Confucius finally understood Yan Yuan's concern and said with deep meaning, "Haven't you observed carefully? The greatest sorrow is a dead heart—a dead body is less serious. The sun rises in the east and sets in the west; all things follow their own laws. Those with eyes and feet succeed by acting in harmony with nature's rhythm. I live and teach by this principle. You and I often miss each other by a hair's breadth—isn't that sad? What you do now is mostly what I once did; you learn from my past actions, yet you think I'm hiding some secret from you. That's like searching a busy market for a horse that stands still—impossible! Time flows like water; in a blink, you are no longer the you of a moment ago, and I am no longer the I you once knew."
Yan Hui began to understand: merely following in others' footsteps was not enough—one must act according to the natural laws of all things.
The idiom "Unable to Catch Up" means seeing the dust raised by those ahead and being unable to overtake them. Later, it is used as a metaphor for falling far behind others or other things. It is also used as a humble expression, indicating that one is far inferior to the other party.
Source: *Zhuangzi*, "Tian Zifang"
Meaning of the Idiom: Later, the Chinese idiom "望尘莫及" came to describe seeing the dust raised by those ahead and being unable to overtake them.