Star Trek: Deep Space Nine1993

[Bashir tells Garak the story of The Boy Who Cried Wolf]

Dr. Julian Bashir:
It's a children's story, about a young shepherd boy who gets lonely while tending his flock. So he cries out to the villagers that a wolf is attacking the sheep. The people come running, but of course there's no wolf. He claims that it's run away and the villagers praise him for his vigilance.

Elim Garak:
Clever lad. Charming story.

Dr. Julian Bashir:
I'm not finished. The next day, the boy does it again, and the next too. And on the fourth day a wolf really comes. The boy cries out at the top of his lungs, but the villagers ignore him, and the boy, and his flock, are gobbled up.

Elim Garak:
Well, that's a little graphic for children, wouldn't you say?

Dr. Julian Bashir:
But the point is, if you lie all the time, nobody's going to believe you, even when you're telling the truth.

Elim Garak:
Are you sure that's the point, Doctor?

Dr. Julian Bashir:
Of course. What else could it be?

Elim Garak:
That you should never tell the same lie twice.