“You see, happiness ain’t a thing in itself – it’s only a contrast with something that ain’t pleasant. That’s all it is. There ain’t a thing you can mention that is happiness in its own self – it’s only so by contrast with the other thing. And so, as soon as the novelty is over and the force of the contrast is dulled, it ain’t happiness any longer, and you have to get something fresh.”

Captain Stormfield’s Visit to Heaven, by Mark Twain