Mencius uses mountain trails as a metaphor to warn disciple Gaozi: constant practice clears one’s moral mind, yet neglect lets weeds of desire block it. He reminds people to sustain unceasing self-cultivation to avoid spiritual stagnation.
Confucius states forty is a mature milestone for self-cultivation. If one is still widely disliked by forty, deep-seated flaws make moral improvement nearly impossible, urging timely self-reflection and correction of faults early in life.