A fox was hungry . She saw a bunch of grapes. She jumped to get them. She jumped again and again but could not get them. She went away saying that the grapes are sour.
The moral being- It is easy to despise what you cannot get.
We have been brought up thinking how wrong the fox is. The grapes need not really be sour after all. So wrong to scorn, to revile something.
But does it matter if the grapes were in fact sweet? It was really sour for the fox! Something that could not remove the hunger of the fox definitely left a sourness in its heart. The grapes were sour...
Well, if the fox did think so while going on its way, it definitely would have become easier for her to make peace with unfulfilled wishes and move on to new hopes.