Compare the lies in Cecily's diary to Algernon's having secret identities.

Algernon and Cecily make up elaborate stories that don't really assault the truth in any serious way or try to alter anyone else's perception of reality. While Algernon has invented a fictional friend, "Bunbury," an invalid whose frequent sudden relapses allow Algernon to wriggle out of unpleasant or dull social obligations, Cecily is more intrigued by the idea of wickedness. This idea, rather than the virtuous-sounding name, has prompted her to fall in love with Jack's brother Ernest in her imagination and to invent an elaborate romance and courtship between them.