The simple smile has no implied meaning. Because of happiness so they smile. For example, someone won a contest, others may succeed in finding a job, and friends see each other after a longtime, etc. Vietnamese believe that smiles give them a better life even they are not rich now. A smile expresses their wishes in life and makes them stronger to overcome difficulties. For example, a farmer smiles looking at their field, a business man smiles as he get a lot of customers, etc. Sometimes, Vietnamese also smiles as a crowd smiles or they do not know what to do. For student, they smile because they do not know how to reply a hard question from their teacher. Simply, they smile to express their emotions.