1. The elegy of decadent dreams refers to the decadent dreams that cannot be realized, and it is an endless lament for the lives of the deceased.
2. Old dreams in Liangcheng mean that there are only old dreams in an empty city, and only old dreams are kept in an empty city. People go empty, but their feelings and dreams are not completed, just like the endless acacia, which is unforgettable.
3. Conan's dream is to describe a big dream and compare it with an empty happiness.