The self-deception of Blanche DuBois in Tennessee Williams' play A Streetcar Named Desire is symbolized clearly in her purchase of a paper lantern to hang over a naked bulb in Stella and Stanley's New Orleans apartment. As symbolized in that action, Blanche seeks to do all she can to convince herself and others that things are much more lovely and more perfect than they truly are. She lies about her drinking, about her age, about the loss of the family estate... in short, she tries to deceive herself and others when it comes to unpleasant, hard truths. Her costume jewelry and her frequent baths may be seen as similarly symbolic of her self-deception; she wishes to continue to think of herself -- and to have others think of her -- as wealthy and as a "true Southern belle" (not, as she possibly may have been at the hotel in Laurel, as a prostitute).
Even with all her faults, Blanche remains the most remembered and probably the most pitied character in the play. People like to imitate or mock her occasionally (at least some of my friends do!), but we're probably all a little like her, repressing or avoiding some of the harsh truths at least for a while.