USMC Vietnam veteran who became Minneapolis Roosevelt High teacher

In 1972 a newly discharged young Marine platoon Sargent returned to civilian life as my science teacher at Roosevelt High School in Minneapolis. 

I think it was his way of getting Vietnam behind him by explaining in great detail how a platoon Sargent survived the rice patties of Vietnam. He made diagrams on a chalk board of how he would always keep his men spread out and he would typically be in the middle of the patrol. He never talked about combat or the men he probably lost. 

I ran into him 20 years later and he had no recall of talking about his Vietnam experience in his science class but I remember it like it was yesterday.