吃不到的葡萄是酸的嗎？

The Fox and the Grapes
One hot summer's day a Fox was strolling through an orchard till he came to a bunch of Grapes just ripening on a vine which had been trained over a lofty branch.

"Just the thing to quench my thirst," quoth he. Drawing back a few paces, he took a run and a jump, and just missed the bunch. Turning round again with a One, Two, Three, he jumped up, but with no greater success.

Again and again he tried after the tempting morsel, but at last had to give it up, and walked away with his nose in the air, saying: "I am sure they are sour."

It is easy to despise what you cannot get.

「吃不到的葡萄是酸的」是諷刺某些人因自己無法得到或無法做到，心理不平衡而自我安慰的一種心態。
即如魯迅筆下的阿Q精神一樣。
這寓言教訓我們︰
凡事應面對現實，知道自己的不足從而增值自己，才會進步。而不是死要臉子、自欺欺人。