This research draws on the geographical concept of situated lay-knowledge to highlight how the formation of tourists’ attitudes to travel destinations challenges the theoretical foundation of the theory of planned behavior (TPB). It suggests that situated lay knowledge is dynamic as opposed to static, which is the accepted basis of TPB, and subsequently, proposes a “Situated Lay-Knowledge Travel Behavior Model” (SLKTB). The model was tested in a mixed methods approach where Chinese tourists, who knew little about Portugal, encountered Portuguese culture and cuisine in Macau. The overall results demonstrate that the formation of tourists’ attitudes about travel destinations is not preexisting or static but dynamic and created from their ongoing encounters.