[1] He was one of three children born to Marie Christine (née Schultz) and George Hamilton Lamb, his father being a Country Party member of the parliament of Victoria.

[3] Lamb attended Box Hill High School before taking up a scholarship at Scotch College, Melbourne.

He qualified as a pharmacist at the Victorian College of Pharmacy in 1959, where he was a member of the Young Labor Association and active in the New Theatre.

He later worked for periods in South Croydon and Camberwell before becoming manager of a pharmacy at the Northland Shopping Centre in Preston.

As a backbench member in 1973, Lamb and David McKenzie introduced the Medical Practice Clarification Bill which, if passed, would have allowed abortion in the Australian Capital Territory.