My family members have many story about this: The children were relocated to rural areas, bomb shelters were built on the pavements etc.. what seemed surreal to me was my uncle story, just as the B52 was bombing the Yen Phu power plant he was standing on the other side of the lake sipping tea and look at the explosion. That very same uncle survived through the famine which killed up to 2 millions of Vietnamese. So for him, having food to eat even under constant bombing is better already. So I don't think it's due to any kinds of philosophy, it's just that we never know that life could be better than that.