According to Huang Jui-hsiang, who holds a doctorate in soil science and is an avid reader of China's classical literature, Laozi was especially adept at using water as a metaphor to express his thoughts because he was from southern China, where lakes and rivers abound.
喜讀傳統經典的土壤學博士黃瑞祥發揮高度想像力說，楚文化的南方多水，因此老子善以江海的特性做比喻。