This poem is a beautiful poem, which expresses that time goes by, years are ruthless, life is short, and we cherish the feelings of the moment. Among them, "one step is shallow and two steps are deep" can be understood as the passage of time step by step, "three steps when a teenager is old" means that time is ruthless, childhood is fleeting, "one walks two lines" expresses the experience and footprint on the road of life, and "three steps without trace" means that time flies. Looking back, many things have disappeared in the torrent of time.