In fact, all the so-called Duke of Zhou are fake. This dream of yours reflects your recent subconscious anxiety, or is caused by an anxious behavior. In fact, there is no warning in the dream, just a reflection of your psychological state. If you have time, you can read Freud's Interpretation of Dreams and Jung's The True Meaning of Dreams. Although these two books are difficult to understand, they will help you understand what dreams are all about.