system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is "Fortunate Son" the stereotypical song for the Vietnam war.

Feels like people cant make a movie or game about the Vietnam war that doesnt have the song Fortunate Son in it.
gpt
It was a song written about the Vietnam War during the Vietnam War. It was about the feeling that people were dying for no reason, and the people with money and power could avoid fighting while the poor people couldn’t.  
It was a good song, so the people who were against the Vietnam War started playing it a lot.
So it became associated with the Vietnam War then.  
I think a lot of our modern association with it comes from its use in Forrest Gump in 1993 though.