Anyone who does not see the vanity of the world is very vain himself. So who does not see it, apart from young people whose lives are all noise, diversions, and thoughts for the future? But take away their diversion and you will see them bored to extinction. Then they feel their nullity without recognizing it, for nothing could be more wretched than to be intolerably depressed as soon as one is reduced to introspection with no means of diversion.