Sillitoe left school at the age of 14, having failed the entrance examination to grammar school. He worked at the Raleigh factory for the next four years, spending his free time reading prodigiously and being a "serial lover of local girls". He joined the Air Training Corps in 1942, then the Royal Air Force, albeit too late to serve in the Second World War. He served as a wireless operator in Malaya during the Emergency. After returning to Britain he was planning to enlist in the Royal Canadian Air Force when it was discovered that he had tuberculosis. He spent 16 months in an RAF hospital.