He played basketball for Hermann High School and graduated in 1947. His senior year, his high school basketball record was 43-7 and placed fourth in state playoffs in only one class of schools.Gosen attended Moberly Junior College from 1947 to 1949, and the team record was 60-6. He then attended the University of Missouri-Columbia from 1949 to 1951 and graduated in 1951.
He then served in the U.S. Air Force from 1951 to 1955.
Gosen started coaching high school basketball at Mokane High School 1955, then went to Sullivan High School and coached there from 1956 to 1960. He returned to Hermann High School for the 1960-61 school year and retired in 1990 as the athletic director
He was a basketball coach for 18 years, and 13 of those years were at Hermann High School. He also coached golf, volleyball, cross country, softball, baseball and track.
His basketball coaching record from 1968 to 1972 was 153-10. His record at Hermann High School was 286-112, a 72 percent winning percentage. His teams went undefeated in Four Rivers Conference play for five straight years, with 18 tournament championships, five district championships and four consecutive Final 4 appearances.
His team finished third place three times in state championship play in Class M, 1968, 1969 and 1970 and took the state championship in Class M in 1970.