In divination, the watershed is used as a metaphor, indicating that a certain time or an event has a great influence on a person's life. Just like the watershed of two roads, life will go to two completely different roads and produce two completely different results. This concept emphasizes the uncertainty of life and the impermanence of fate.
It should be noted that the above explanation may not be applicable in all cases. Personal destiny and life planning are influenced by many factors, and it is impossible to simply explain a person's life trajectory with a watershed.