Bordedom

"Nothing is so intolerable for man as to be in a state of complete tranquility, without passions, without business, without diversion, without effort. Then he feels his nothingness, his abandonment, his inadequacy, his dependence, his helplessness, his emptiness. At once from the depths of his soul arise boredom, gloom, sadness, grief, vexation, despair."

Blaise Pascal, Pensées, 515.