Collett attended the Commonweal School, Swindon, England from 1963 to 1970[2] and St Peter's College, Oxford, taking a Bachelor of Arts in Modern History in 1973. He served in the Devonshire and Dorset Regiment and in 1974 attended the Royal Military Academy Sandhurst. In 1983–84 he attended the Army Staff College, Camberley. In 2002 he earned a Master of Arts in Biography at the University of Buckingham.[2]
From 1981 to 1982 he served as a company commander with the Western Frontier Regiment on secondment to the Land Forces of the Sultan of Oman. In 1983 he was an instructor with the British Military Advisory Team in Zimbabwe. In 1984 he was promoted to major and transferred to the 6th Queen Elizabeth's Own Gurkha Rifles, and was posted to Hong Kong, where he served from 1985 to 1992, including tours as brigade major 48 Gurkha Infantry Brigade and brigade major Brigade of Gurkhas. In 1991, he was promoted to lieutenant-colonel and was given command of the 6th in Hong Kong and was garrison commander for the British Forces in Brunei from 1992 to 1993.
Since 1994, he has been managing director of Gurkha International Manpower Services Ltd and Gurkha International (Hong Kong) Ltd, both in Hong Kong; website www.gurkha.com.hk. He is vice chairman of the Hong Kong and China Branch of the Royal British Legion and vice chairman of the Asia Africa Committee of the Hong Kong General Chamber of Commerce.[3]
