Love

Why does it hurt so much? Why does your heart physically ache when you lose someone you love? Why can't getting over someone be easy?
How does happen? How do you fall in love with someone you never thought you would? How do you end up loving someone so much that you didn't think it was possible to love someone that much? How do you stop thinking about that person? How do you make the pain go away? How do you get over someone?