Pensées

He who does not see the vanity of the world is himself very vain. Indeed who do not see it but youths who are absorbed in fame, diversion, and the thought of the future? But take away diversion, and you will see them dried up with weariness. They feel then their nothingness without knowing it; for it is indeed to be unhappy to be in insufferable sadness as soon as we are reduced to thinking of self, and have no diversion.

—Blaise Pascal, Pensées.