"Sour grapes," as the fox said when he could not reach them.

Understand the thought

Meaning in plain English

Someone may dismiss a desired thing after finding they cannot obtain it. The unreachable grapes picture a change in the account of its value, without proving that every negative judgement after disappointment is dishonest.

What the words are saying

The fox calls the grapes sour after being unable to reach them in the saying’s picture. A useful reading asks whether the criticism rests on newly discovered information or mainly on the frustration of not having the thing. It is possible to reconsider a preference honestly, and disappointment can reveal what mattered or did not matter. The saying should not make every changed opinion suspect. Its point is to examine the basis for the judgement rather than accept either the earlier desire or the later dismissal as conclusive. It describes a possible response to frustration, not evidence of a particular person’s hidden motives.

Everyday example

A participant is disappointed not to join a workshop and checks its actual content before repeating that the session would have been worthless anyway.

When to use it

Use it when rejection of a formerly desired option may be a response to not obtaining it.

Agent-assisted editorial interpretation. This explains the words; it does not by itself verify their author or earliest origin.