I dreamed that I caught a black swan from the river.

In fact, it is better not to believe these things, perhaps because you are under great pressure at ordinary times. Of course, people in China generally say that dreams are the opposite. A swan is caught in a dream, and it is black. As the crow said, the black swan must be uglier than the white swan, which means that the ugly duckling will become a swan and something good will happen to you.