Caine is regarded as a British cultural icon, with Mairi Mackay of CNN stating: "Michael Caine has been personifying British cool since the swinging sixties. He has brought some of British cinema's most iconic characters to life and introduced his very own laid-back cockney gangster into pop culture. He doggedly retained a regional accent at a time when the plummy tones of Received Pronunciation were considered obligatory. It is a sweet irony that his accent has become his calling card." With his distinctive voice and manner of speaking, Caine is a popular subject for impersonators and mimics. Most Caine impressions include the catchphrase "Not a lot of people know that." The catchphrase emanates from Caine's habit of informing people of obscure "interesting facts" that he has collected. Referring to Caine as being the "biggest mine of useless information", Peter Sellers initiated the catchphrase when he appeared on BBC1's "Parkinson" show on 28 October 1972 and said: