Please analyze the following quotation from The Importance of Being Earnest:
" I do not approve of anything that tampers with natural ignorance. Ignorance is like a delicate exotic fruit; touch it and the bloom is gone" Act 1
Lady Augusta Bracknell, aunt of Algernon and mother of Gwendolyn expresses this phrase during her interview with Jack Worthing, where she is weighing whether Jack is a suitable future husband for her daughter. At the question of whether Jack knows "everything or knows nothing", Jack wisely answers that he knows "nothing" at all.
This pleases Lady Bracknell, who says that the natural state of things is best than the application of outside influences. This sounds like a pretty acceptable tenet, except for the fact that Lady Bracknell is referring to ignorance, which is what makes it paradoxical.
This is Wilde's way to mock the "educated classes" in England who assume that class equals intelligence. Since Lady Bracknell displays a tremendous amount of ignorance saying this phrase, it solidifies Wilde's satire that the upper-classes are essentially rich simpletons.
ignorance is like an exotic fruit
is no only a metaphor that does not quite match the original noun, but it is also hyperbole; granting ignorance a trait that deems it "exotic" is placing ignorance in an enigmatic and unique pedestal to which it certainly does not belong.
Hence, Lady Bracknell is essentially saying that it is the right of the rich to live in oblivion and not be "bothered" with the nuisances of education, knowledge, or current events. The problem is that she compares ignorance, which is common place, to something exotic, which is unique. This is what makes the irony more obvious.