The more quickly people reach an understanding of negative events, the sooner they recover from them. […] Virtually all tests […], however, have examined people’s understanding of negative events. The AREA [attend, react, explain, and adapt] model is unique in predicting that explanation also leads to the diminution of affective reactions to positive events. We predict that anything that impedes explanation—such as uncertainty—should prolong affective reactions to positive events. […] These studies highlight a pleasure paradox, which refers to the fact that people have two fundamental motives—to understand the world and to maintain positive emotion—that are sometimes at odds.

Timothy Wilson and Daniel Gilbert, ‘Explaining away: A model of affective adaptation’, Perspectives on Psychological Science, Vol. 3, No. 5 (September, 2008), pp. 377-378