There were places we would go at midnight
There were secrets that nobody else would know
There's a reason but I don't know why
I don't know why
I don't know why
I thought they all belonged to me

Who's that girl?
Where's she from?
No she can't be the one
That you want
That has stolen my world
It's not real, it's not right
It's my day, it's my night
By the way
Who's that girl living my life?
Oh no, living my life
[ Lyrics from: http://www.lyricsfreak.com/h/hilary+duff/whos+that+girl_10141907.html ]
Seems like everything's the same around me
Then I look again and everything has changed
I'm not dreaming so I don't know why
I don't know why
I don't know why
She's everywhere I wanna be

Who's that girl?
Where's she from?
No she can't be the one
That you want
That has stolen my world
It's not real, it's not right
It's my day, it's my night
By the way
Who's that girl living my life?

I'm the one who made you laugh
Who made you feel
And made you sad
I'm not sorry
For what we did
For who we were
I'm not sorry
I'm not her

Who's that girl?
Where's she from?
No she can't be the one
That you want
That has stolen my world
It's not real, it's not right
It's my day, it's my night
By the way
Who's that girl living my life?
Oh no, living my life