It can and should be said about every fiction, as a healthy reminder to yourself. Fiat money, government and property rights are complete abstractions, completely abused and tarnished beyond all limits. A verbal agreement is on a much closer level to reality. Even people who have never heard of money or owned property will take a man up on his word. As for sexual consent it is not something abstract at all. It's not words. It is the will of a person and something that can never be misunderstood.