you reckon there's more than one you in play? since it's the same word, I'd assume it refers to same subject throughout ("you walked..." "you're so vain" "don't you?") and the song can only be about you
1) you're warren beatty or someone else intimately familiar with carly simon - this song may be about you, and you probably think it is
2) you don't know carly simon personally, so this song isn't specifically about you - but the meaning of the song might apply to you too; if you think it does, it does
― niels, Thursday, 26 November 2015 09:20 (eight years ago) link