Cao Cao was a famous militarist in the Three Kingdoms Period (220-280).
One summer, he led the army for an expedition. At that time, it was very hot, and the sun was shining wildly. The soldiers walked for an entire morning and drank up their water, but there was no water source nearby. The soldiers were tired, thirsty and hot, and almost couldn’t march ahead any longer.
Cao Cao ordered the solders to look for water everywhere, but failed. Having no other choice, Cao Cao asked soldiers to dig a well. The soldiers dug a very deep well but no water was found. The soldiers lay on the ground, and didn’t want to walk any more. Cao Cao was very anxious—if the army stayed in this place, the soldiers would run up their vitality, and could die here because of thirsty. He must think of an idea to make the soldiers move on!
An idea suddenly came to him. He climbed to a high place, looked around, and shouted to the soldiers, “Water! Water!”
Hearing the shout of their general, the soldiers, who were suffering thirst bitterly, immediately stood up from the ground. Cao Cao said, “Just now, I had a look at this place. I went this way before. There is a plum forest just on the other side of the hill. The plums are big and sweet, and we can enjoy the plums as many as we can. Then, will we still be thirsty?”
Hearing his remarks, the soldiers refreshed themselves, and slavered when thinking of the acidic plums. They didn’t feel as bad as before. Cao Cao then made use of this opportunity to lead his army to march ahead, and finally reached the destination.
In fact, there was no plum forest at all, and it was just a small trick played by Cao Cao.
This story comes from Essaysand Criticism. Later, this proverb is used to describe that when a wish can’t com true, somebody will have to console himself with daydreaming.