Be Yourself Everyone Else Is Already

This is widely considered a misattribution. No researcher has located this phrase in any of Wilde's plays, essays, letters, or the novel The Picture of Dorian Gray. Wilde did write about selfhood and performance — De Profundis contains the verified line "Most people are other people. Their thoughts are someone else's opinions, their lives a mimicry" — but that is a more complex and characteristically Wildean take on the same theme. The "be yourself" phrasing appears to be a 20th-century condensation attached to his name.