It takes a while for a national trauma to sink in and register.
In 1924, six years after the close of that war, "Storm of Steel" was published in Germany, portraying war not as tragedy and a fraud but as a great, mysterious, elemental force to be experienced and survived.
Speaking of nostalgia, here's an update on the classic Marxist concept of "ideological misrecognition". For Marx, people need to be enlightened about their exploitation so that they can cast off the false beliefs of the status quo and embrace revolution. Later "critical theorists" identified misrecognition as active propaganda and not just an effect of exploitation. More recently, misrecognition has been understood as nostalgia for a lost object which is actually fictitious (e.g., an idealized vision of a pre-colonial order in the Third World).
That sounds a lot like "First Blood".
But it also sounds a lot like Donald Trump talking about making American "great again."
There is the question of the exact psychological dynamic of how misrecognition works, as well as the question of whether there is ever any real liberation from misrecognition, or if all cognition is misrecognition.
There is an anthropological and psychological mystery of why American Indians, when they watch movies about the "wild west", tend to root for the cowboys and not the Indians.
But is income inequality really growing? Bill Gates is the wealthiest man in the world today, with a worth of $80 billion; he was born into wealth and went to the best schools. One century ago, John D. Rockefeller was worth $340 billion and Andrew Carnegie $310 billion; they were both born into modest circumstances (in fact, into poverty, by today's standards). By historical standards, income inequality has been shrinking, but upward mobility has been stifled. And historically, income inequality (Equality of Condition) never really bothered Americans, American life was always about upward mobility (Equality of Opportunity).
But the followers of Sanders don't use the less rhetorically appealing battle cry that "It is becoming more difficult to move up in the world." Rather, they use the stark language of "inequality" from the civil rights movement -- even though the civil rights movement of the 1950s and 1960s was really limited to equality before the laws (Equality of Opportunity), not income equality. Sanders supporters want to move up in the world, but they cannot admit it, not publicly, and not even to themselves.