Sleep, riches, and health to be truly enjoyed must be interrupted. – Johann Paul Friedrich Richter, Flower, Fruit, and Thorn

Enduring habits I hate…. Yes, at the very bottom of my soul I feel grateful to all my misery and bouts of sickness and everything about me that is imperfect, because this sort of thing leaves me with a hundred backdoors through which I can escape from enduring habits. – Friedrich Nietzsche, The Gay Science, 1882

I reckon being ill as one of the great pleasures of life, provided one is not too ill and is not obliged to work till one is better. – Samuel Butler, The Way of All Flesh, 1903