Dunn and Norton ground the 'make it a treat' principle in a fundamental feature of human psychology called hedonic adaptation: people adjust to positive stimuli remarkably quickly, returning to baseline satisfaction regardless of the quality or quantity of good things in their environment. The first bite of a favorite food tastes better than the tenth; the first month in a new house feels more exciting than the twelfth.

The practical implication the authors draw is counterintuitive: deliberately limiting access to pleasurable things preserves their pleasure. An experiment Dunn conducted found that people who were asked to go without chocolate for a week reported more enjoyment when they finally ate it than people who had continuous access. The scarcity reset their hedonic baseline.

This principle maps directly onto spending behavior and consumer choice. The proliferation of streaming services, on-demand delivery, and instant consumer access to virtually any product has saturated the hedonic experience for many people — everything is available, so nothing feels special. Strategically reintroducing scarcity — eating at a favorite restaurant monthly rather than weekly, taking vacations that are planned and anticipated rather than impulsive and frequent — can restore the pleasure that abundance has flattened.

For financial planning, this is a genuine alignment between happiness research and spending discipline. Reducing consumption frequency of pleasurable things simultaneously saves money and increases the happiness return per dollar spent — a rare case where the psychologically optimal strategy and the financially optimal strategy point in the same direction.

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