Take the happiest man, the one most envied by the world, and in nine cases out of ten his inmost consciousness is one of failure. Either his ideals in the line of his achievements are pitched far higher than the achievements themselves, or else he has secret ideals of which the world knows nothing, and in regard to which he inwardly knows himself to be found wanting.

Lectures VI and VII, "The Sick Soul" - The Varieties of Religious Experience (1902)