The tourist brochures call Thailand the "Land of Smiles". In this one instance they probably got it right. But that does not mean that the Thai culture is one of simplicity and complete harmony.
It is a complex society and a newcomer probably won't go more than a few hours without committing the inevitable cultural faux pas.
The difference between the Thai culture and so many others is that when you've done something foolish, and maybe even insulting, most people here will simply smile and laugh it off.
Buddhism asserts the most influence on how the Thai people see their world and live their lives.
Learn more about this multifaceted culture and its smiling people by going to the links provided.