John Barleycorn is an autobiographical novel by Jack London dealing with his enjoyment of drinking and struggles with alcoholism.

Key stages are his late teen years when he earned money as a sailor and later in life when he was a wealthy, successful writer.

[2] The first recorded use of pink elephants as the stereotypical hallucination of the extremely drunk[3][4] occurs at the beginning of chapter two: There are, broadly speaking, two types of drinkers.

There is the man whom we all know, stupid, unimaginative, whose brain is bitten numbly by numb maggots; who walks generously with wide-spread, tentative legs, falls frequently in the gutter, and who sees, in the extremity of his ecstasy, blue mice and pink elephants.

To them, John Barleycorn sends clear visions of the eventual pointlessness of life and love and struggle.