Last Year in Viet Nam (1971)

Featured on the DVD "first works". The film shows a man trying to forget his Vietnam Memories by throwing his war-memorabilia (photos, medals) away. Through the story mixed are fragments he shot while stationed in Vietnam. This gives the film some debt.
The movie was shot while he was studying at NYU, a teacher there convinced him to look into his own experience's for making a good film. Being a Vietnam veteran it was obvious he chose that as a subject. The theme about a veteran trying to cope with his war experiences is a subject that comes back in several of his later movies, particularly in Born on the 4th of July.
It is a pretty good first and worth watching.