Immanuel Kant's Categorical Imperative states:
—Act only according to that maxim whereby you can, at the same time, will that it should become a universal law.

In other words, one should pursue an action only if they would be happy to engage in this action over and over again. And only if they would be pleased with others acting in the same way, over and over again. As such, lying is a bad idea because if done systematically, it will eventually damage a person's reputation; if done by everyone repeatedly, it will undermine the entire system of trust in society.

The Categorical Imperative is immensely helpful even beyond morality. People have a behavioral tendency to evaluate each decision in isolation (i.e., narrow framing) without accounting for how multiple similar choices would add up over the long term (i.e., broad framing). For example, little upside exists in reading a good book for 30 minutes on a given day. Will this half-hour change your life? No. But if you read for 30 minutes a day, every day, in a few years or maybe even months, you will become a different person.

John D. Rockefeller, the founder of Standard Oil and arguably the wealthiest person in modern history, had an intuitive understanding of how small, seemingly inconsequential actions when practiced consistently, lead to riches. Unlike other refiners who relied on whatever barrels were available, Rockefeller would seek to produce barrels in-house and make them as light as possible to save on transportation costs. Achieving even a tiny reduction of a barrel's weight mattered for it would add up to a sizeable extra profit over millions of barrels.

Frugal in business, Rockefeller was equally opposed to undue expenditure in everyday life—even though his net worth represented about 1.5% of the entire US GDP. For instance, to avoid losing brand new golf balls in water hazards, when in their proximity, he would deliberately switch to old golf balls. And having encountered profligate players using new balls next to water hazards, Rockefeller would say: "They must be really rich!"

Kant's Categorical Imperative and broad framing up the ante of a miniscule penny-saved-penny-earned. A penny saved a billion times is ten million dollars earned.