YOU SAID:
you're so vain i bet you think this song is about you
INTO JAPANESE
あなたはきっとこの曲はあなたについてだと思うので無駄
BACK INTO ENGLISH
Think you I am sure this song is about you so vain
INTO JAPANESE
きっとこの曲はあなたについてあなたはだから無駄だと思う
You've done this before, haven't you.