Aesop's Fables: The Fox and the Grapes: An Analysis
A hungry fox saw some fine bunches of grapes hanging from a vine that was trained along a high trellis and did his best to reach them by jumping as high as he could into the air. But it was all in vain, for they were just out of reach. So he gave up trying and walked away with an air of dignity and unconcern, remarking "I thought those grapes were ripe, but I see now that they are quite sour."
The fox, here, finds that he is unable to obtain the grapes and, therefore, attempts to cause himself to believe that they weren't really what he wanted to begin with.
What we see above is a person finding something he wants, finding he
can't get it, and talking lowly about the thing he wanted. It is very nearly the case that the individual is working to clear his mind about the fact that he wasted time/money/effort.
A Modern Example
A man is browsing the internet for a piece of jewelry for his wife. His wife likes amethyst, which isn't an expensive gem, but she likes fancy home-made jewelry the best. As such, the man finds his way to ebay, where an auction for a beautiful amethyst and topaz brooch lies in wait for our protagonist. The auction ends in a week, and there is no "Buy-it-now" option. Throughout the week, the man continuously checks to make sure he is not outbid, but, at the last moment, he finds that another bidder has won the auction. In his disgust for having wasted nearly a week for naught, he exclaims, "I bet the brooch was ugly in person anyway - photoshop is so simple these days."
If you have any other ideas to point out, please, please make mention of them in the comments section below. If there is something important that I've missed, I will add it to the article and cite your comment with thanks for providing the information (with your permission).
If there is another interpretation, please share it, I'm quite interested to hear it and, again, may use it to improve my article and cite your comment (with your permission).