You live only once The logician would argue, You only live once should be rewritten as You live only once, with only next to the thing it qualifies, once. The logician would be unbearably pedantic, but there is a grain of good taste in the pedantry. Writing is often clearer and more elegant when a writer pushes an only or a not next to the thing that it quantifies. In 1962 John F. Kennedy declared, “We choose to go to the moon not because it is easy but because it is hard.” That sounds a lot classier than “We don’t choose to go to the moon because it is easy but because it is hard." Steven Pinker, The Sense of Style grammar
You cannot consume what is not produced The only law of economics that I believe in is Hamming’s law: “You cannot consume what is not produced.” There is not another single reliable law in all of economics I know of which is not either a tautology in mathematics or else sometimes false. Richard Hamming, The Art of Doing Science and Engineering: Learning to Learn Scientific writing economics