Oscar Wilde is an incredibly funny and witty writer. His humor in The Importance of Being Earnest relies on creating absurd situations and characters whose lack of insight causes them to respond to these situations in inappropriate ways. For example, Lady Bracknell’s preoccupation with her own parties and lack of sympathy for invalids makes her react to the news of Bunbury’s illness in an exaggeratedly cold manner:
Well, I must say, Algernon, that I think it is high time that Mr. Bunbury made up his mind whether he was going to live or to die. This shilly-shallying with the question is absurd….I would be much obliged if you would ask Mr. Bunbury, from me, to be kind enough not to have a relapse on Saturday, for I rely on you to arrange my music for me. (I.130)
Most of us recognize that death by illness isn’t a matter of conscious choice and would take pity on the dying Bunbury. Not Lady Bracknell. She’s more concerned with the propriety of her music arrangements. She’s frivolous, worrying about style over the life-and-death struggle of Bunbury. The entire play runs similarly – with characters responding to situations in ways that are inappropriate give the situation, either too serious or too flippant. Such exaggeration gives Earnest its distinctive brand of Wildean humor.
Keep an eye out, too, for Wilde’s patented epigrams – succinct, witty, paradoxical sayings. They are often general reflections on life, and can be lifted straight out of the text and used on your friends. For example: "All women become like their mothers. That is their tragedy. No man does. That's his" (I.228). Wilde’s ability to craft these sayings is what made him famous, and his true source of inspiration for the play. In a letter to an actor-producer friend with the scenario (hoping to get an advance, as he was in dire straits for money) Wilde admitted as much – "The real charm of the play, if it is to have charm, must be in the dialogue" (source: "Appendix: Letter to George Alexander." The Importance of Being Earnest and Other Plays. Ed. Michael Cordner. Oxford U, 2008).