Jocelyn was born on 3 May 1921 in Johannesburg to Polish born Salomon Freundlich and Elma née Ginsberg. Salomon worked as an attorney and died in 1934 when Jocelyn was thirteen. When he was seventeen he travelled to England and was listed as a student.

Jocelyn is listed as a direct entry airman who joined as an observer when he was eighteen. On 29 August 1940, Jocelyn was awarded the DFM while flying Blenheims with 110 squadron. He had completed 38 sorties and over 100 hours of flying.

On 21 May 1943, Mosquito B.Mk.IV DZ464 departed RAF Marham at 19.45 hrs on a strike against locomotive sheds near Orleans, France. The aircraft was shot down by flak near Le Treport, Normandy returning from the sortie, claiming both crew: Squadron Leader Vernon Harcourt DFC and his observer, W/O Jocelyn Friendly DFM.