The opportunity cost mental model refers to the value of the best alternative forgone when a particular choice is made among multiple options. It highlights the scarcity of resources—such as time, money, and energy—and emphasizes that every decision involves sacrificing potential benefits from other alternatives. Understanding opportunity cost helps us more comprehensively evaluate the true cost of a decision, going beyond just explicit costs, thereby enabling wiser choices. It encourages decision-makers to consider not only the direct gains of the chosen option but also the potential value of the alternatives given up, leading to more optimal allocation of resources.