For over 40 years, one of the biggest mysteries in music was the identity of the subject in Carly Simon’s hit 'You're So Vain.' Fans speculated it was about Warren Beatty, Mick Jagger, or David Geffen. Simon kept the secret for decades, even auctioning off the answer for charity under the condition that the winner never reveal it. In 2015, Simon finally confirmed that the second verse was indeed about actor Warren Beatty, though she noted the song is actually a composite of three different men from her life. Mick Jagger actually provided uncredited backing vocals on the track, which fueled rumors that he was the subject. The song remains a classic of the singer-songwriter era, famous for its sharp lyrics and the intrigue surrounding its inspiration.