Lewis William Arthur O'Brien was born at Point Pearce Mission on Yorke Peninsula in South Australia on 25 March 1930.

His father, who until late in life he had thought was an Irishman, and registered on his birth certificate as Ernest James Patrick Holmes O'Brien, was actually English.

[1] Ernest Holmes/O'Brien came to South Australia as part of an immigrant boy apprentice scheme known as "South Australian Farm Apprenticeship Scheme" introduced by the premier Henry Barwell after World War I. Lewis never met his father, who left his mother before he was born, and returned to England in 1935, remarried and had another family there.

He gained his Intermediate Certificate of education in 1946 from Le Fevre Boys Technical High School at Glanville, South Australia, overcoming extreme difficulties to do so, and gained an apprenticeship as a fitter and machinist with the South Australian Railways, completing in 1952.

[3] While O'Brien was in his later school years and beginning his apprenticeship, he lived at Kumanka Boys' Hostel in Childers Terrace, North Adelaide.

Her father, Eddie Sansbury, had grown up in Point Pearce, and in later life lived with the O'Brien family.