21 in the US in November 1966 and failed to chart in Clark's native UK, as did the follow-up US Top 20 single "Color My World".

During this 1965–66 period, three US hits — "You'd Better Come Home", "Round Every Corner" and "A Sign Of The Times" — did not crack the UK Top 40.

Although largely conforming to the formula established by Clark's previous work with Hatch, "Who Am I" is distinct in its referencing concerns of the 1960s social consciousness, specifically the search for the meaning of life.

The November 1967 issue of High Fidelity magazine featured an essay by Canadian pianist Glenn Gould: The Search for Petula Clark, which Gould was moved to write after hearing "Who Am I" on his car radio, the song striking him as a "document of despair [which] catalogues [the] symptoms of disenchantment and ennui" in contrast to the buoyancy expressed in Clark's earlier hits "Downtown", "My Love" and "A Sign of the Times".

Gould later observed his essay used Petula Clark "as a jumping off point to examine the whole so-called flower-child generation of the mid-60s.