By Scott Slusser | September 16, 2026
Slusser’s Law states that the probability of having forgotten an item increases exponentially with the distance traveled from the point of departure. First formulated by Scott Slusser on September 16, 2026, the law holds that a traveler five minutes from home has a negligible chance of having left something behind, while a traveler thirty or more minutes out is nearly certain to have done so.
The relationship is not linear. Short trips carry almost no risk, and the curve remains flat until a threshold, after which the likelihood of a forgotten item rises sharply. Slusser observed the inflection point at roughly thirty minutes of travel, though the exact threshold may vary by individual and circumstance.
The base law is expressed as P(forgot) ∝ e^d, where d is distance from the point of departure.
Two corollaries follow, and both are functions of the same variable. First, the cost of recovering a forgotten item rises with distance, since the return trip grows with every mile traveled. Second, the value of the forgotten item also rises with distance, since its worth is no longer its replacement price but the cost of everything it now blocks.
Combining the law with its corollaries gives the total penalty of a forgotten item:
L = P(d) × [C(d) + V(d)]
where P(d) ∝ e^d is the probability of having forgotten something, C(d) is the cost of going back for it, and V(d) is the value the item has taken on by being absent. Each term grows with d, so the penalty compounds from three directions at once. This is why the consequence of a forgotten item feels negligible near home and severe once the traveler is far enough out that turning around is no longer a real option.
Slusser’s Law belongs to the family of empirical laws that includes Murphy’s Law and Sod’s Law, but is distinguished from them by its specific domain (forgotten items) and its specific predictor (distance), which together make it testable in a way its more general relatives are not.
Originally published at scottslusser.com/good-mind/slussers-law.