The Exorcist (film) shot that obscured his face, as Friedkin felt that Vandis's face would be connected with his previous role in the Woody Allen film "Everything You Always Wanted to Know About Sex* (*But Were Afraid to Ask)". Vandis had previously played Milos Stavros, an Armenian shepherd who was in love with a sheep. Warners had approached Arthur Penn, Stanley Kubrick, and Mike Nichols, to direct, all of whom turned the project down. Originally Mark Rydell was hired to direct, but William Peter Blatty insisted on Friedkin instead, because he wanted his film to have the same energy as Friedkin's previous film,
Know Who You Are lived with my parents there were some fields over the back and there were always gypsies camping there. They used to have these horses and donkeys and they always looked dead to me. They were not looked after which was sad." Following its lack of success, "Know Who You Are" was quickly deleted by Polydor and has since become a collector's item. The "Rare Record Price Guide" of 2014 valued the single at £80. The song later received greater recognition when a live version was included on "Slade Alive!", which became the band's first hit album when released in 1972.