I'm thirteen, but the way I remember it fom elementary school is:

       Brick wall, waterfall,
    Girl you think you know it all,
    But you don't, I do,
    So POOF with the attitude
    No, wait,come back,
    I think I found a tick-tack,
    Not one, not two,
    But the whole six pack!

I also remember something about "peace, punch, in your face" and, "You got the brains, I got the looks, so...." something, hope it helps!