The original text is huangliang 黃粱 [yellow millet], a byword for dream. This term came from the famous Tang tale “Zhenzhong ji” 枕中記 [The World Inside a Pillow]. It tells a story about the unappreciated Student Lu meets the Daoist master Old Lü in a lodge, who gives him a pillow to sleep with a wonderful dream where he spends a whole life enjoying all the wealth and glory. When Lu wakes up, he is still the poor student, and the lodge meal made of yellow millet is not ready yet (meaning the time he sleeps is very short). Huangliang later became a byword for dreams, especially those good dreams.
About the whole story: The story begins with a Daoist monk called Lü traveling when he meets a man named Lu. This man is unhappy with his life and laments that he was a great man born at the wrong time. The monk responds by asking him that if his life is not happy then whose life could possibly be happy? Lu monologues that a good and happy life ought to have a certain level of prestige, wealth, and glory, and immediately after he finishes speaking he falls into a deep slumber. The monk offers Lu a blue porcelain pillow on which to sleep. The pillow had an opening on each end.
While the man slept he entered the pillow. Inside the pillow, the man was married to a wealthy family and a beautiful wife and became quite rich. He was appointed to be chancellor to the emperor during a time of war, as well. But soon afterwards, his colleagues became jealous and started spreading rumors that Lu was a traitor; the rumors caused an edict that he should be imprisoned. Upon his capture, he told his wife that he had been afflicted to have wanted such a large salary that he should deserve such a fate. He grew old inside the pillow and upon his dying breath wrote a memorandum about his life and divine fate explaining that his strife was in vain. When he died an old man inside the pillow he then awoke in an inn with the Daoist monk. He proclaims that it may have been a dream and the monk responds that “the happiness of human life are all like that.” (Wikipedia)
