Why Don’t We Keep Buying? (And Buying)

A man walks into a store and buys a bottle of water for two dollars. He has more than two dollars left, and the store has more bottles to sell but the man does not buy another bottle. Observation of the transaction suggests that the man values the bottle of water more than the two dollars he forgoes to acquire it. Yet, despite the possibility of repeating the transaction on identical terms, he chooses not to do so.