Much of Sullivan's material for Only Fools and Horses scripts came from his real-life experiences: falling through a raised bar flap, the chandelier falling, his father's poker sessions, his niece working in the police force, and his grandfather falling down holes to claim money. It is arguable that the economic insecurity experienced by the Trotters' and their eventual rise to wealth is based on Sullivan's own personal background, who grew up in a poor household and noted in an interview that he and his friends seemingly had no other opportunities after leaving school apart from low-paid factory work. The success of Only Fools and Horses, however, made him rich.
In 2005 New Years Honours, Sullivan was awarded an OBE for services to drama. On 2 September 2008 John Sullivan was awarded an Honorary Fellowship at Goldsmiths, University of London. He lived in Brighton & Hove
Sullivan died aged 64 on 23 April 2011, following a short illness. BBC Director-General Mark Thompson paid tribute, saying: "John had a unique gift for turning everyday life and characters we all know into unforgettable comedy.