According to Baidu Encyclopedia, the world of mortals comes and goes in dreams. This is the lyric of Yu Yu's song "World of mortals comes and goes in dreams", which was released on 20 19123 October. Some of the lyrics are as follows: Why are you attached to Residual Red if you can't stay? The world of mortals comes and goes in a dream, empty. When the sun sets, the bright moon goes east, but it is hard to bury the true feelings in a heartless hole, and the world of mortals comes and goes.