Taylor Swift reveals subject of breakup hit  Taylor Swift
performs at the Grammys. Photo/AP Taylor Swift performs at the
Grammys. Photo/AP  Taylor Swift has confirmed I Knew You Were
Trouble was written about her ex-boyfriend Harry Styles.  The
23-year-old pop star gave a scintillating rendition of the song
at the ceremony in February as the One Direction heartthrob
looked on, and she found it easy to connect with her emotions as
the person she wrote it about was so close to her.  Swift - who
ripped off a conservative white wedding dress and gyrated on
stage in a sexy black and lace outfit at the BRITs - said:
"Well, it's not hard to access that emotion when the person the
song is directed at is standing by the side of the stage
watching ... You're balancing the analytical side of your brain
which is telling you where to go and how to go there, with the
other side of your brain, which is saying, 'Feel everything
you're singing, and show it on your face. Feel everything
exactly as you felt it when you wrote th