Graeme attended the College from 1955 to 1960. His father had attended the school, Jack (OGC 1922) as well as his brother Paul (OGC 1959). At school he was played football and was part of the rowing crews.  He represented Shannon in the House competitions and received House Colours for athletics. In 1960 he became House Monitor of Knowle House and also reached the rank of Sergeant (Drill) in the cadets.  His dedication to the cadets was called out in the Pegasus, ““I would like to thank Graham Sheahan, our sergeant, for the work he put in during the year. It was he who did the menial jobs that lead to the smooth running of the platoon.”

Graeme went on to become an engineer. He was married to Jeanette (MOC) and they have two children and five grandchildren.