First chorus is from Glukoza`s - the russian pop singer - song http://www.youtube.com/watch?v=Ja7gyv8nYbo, and I think you shouldn`t bother yourself trying to get what she actually meant... That`s pop-music, do you understand?
Anyway, my guess will be like:
Butterflies in my stomach = first, nice feelings occur in your body. When the love is gone - then you only have got memories left in your head.