It's hard when you belong to someone else

It's hard when you really love someone and you know her heart belongs to someone else. It's hard to wake up each and everyday realizing that you are the one that can make her happy and yet you cannot. You just sit there helplessly waiting for her to realize that you are just there by her side and you are the one who will go to the ends of the earth just to see her smile.
And when the time comes that she finally realizes it you will be long gone. Then both of you will look back regretting what could have been. Regretting that each and every moment that you should have had, you should have been happy together.