The Vietnamese are the most optimistic in the world (of 53 nations surveyed by the BVA Gallup poll recently) and it is no surprise to me. It might be related to Doi Moi, and 35 years of peace after nearly 100 years of warfare, against the Barbarian Siamese (Thai), French colonialist and the US (with others).
Optimism might account for fixing 10,000 power lines to one post (but that is common in Asia), fitting 4 people or more on one motor bike (dito), not having (needing?) household heating in this cold north, and that V. jumped 16 places in the world prosperity index in one year to 2010 (77 to 61, Australia is 4th behind Norway, Denmark and Finland).
Speaking of motor bikes, in Hanoi there are 4.5 million people
Another reason for optimism is Tet - Chinese / Vietnamese New Year - everyone gives gifts and no-one works. My association of Tet is violent, going back to 31 January 1968, the Tet Offensive which marked the turning of the
war against the US (with others). But now, people are happy, and give orange trees to loved ones:
often home delivered.