It is difficult to live without opium after having known it because it is difficult, after knowing opium, to take earth seriously. And unless one is a saint, it is difficult to live without taking earth seriously.

Cocteau frames opium not merely as a physical dependency but as a metaphysical temptation: it alters perception so radically that ordinary life (“earth”) can feel trivial, unreal, or unworthy of earnest engagement. The second sentence sharpens the dilemma—most people are not “saints,” i.e., they cannot sustain a detached, spiritual indifference to worldly concerns. Opium offers an artificial shortcut to that detachment, but once the drug has supplied a sense of transcendence or distance, returning to the seriousness of daily obligations becomes psychologically difficult. The quote thus captures addiction as a conflict between altered consciousness and the moral/practical demands of ordinary life.