Was a skilled musician, and played the trumpet and guitar professionaly during the second world war.
When Peter Sellers and Stanley Kubrick were stuck for an ending for Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964), it was Milligan who suggested the use of the Vera Lynn song "We'll Meet Again".
Wrote a series of books detailing his experiences in World War Two and afterwards: "Adolf Hitler: My Part In His Downfall", "Rommel? Gunner Who?", "Mussolini: My Part In His Downfall", "Goodbye Soldier", "Monty: My Part In His Victory", "Peace Work", "Where Have All the Bullets Gone?".