“The Fox and the Grapes”
One of Aesop's fables. A fox tries many times to pluck some grapes that dangle invitingly over his head, but he cannot reach them. As he slinks away in disgust, he says, “Those grapes are probably sour anyway.”
“Sour grapes” refers to things that people decide are not worth having only after they find they cannot have them.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.