Why is it hard for me to understand?

This is about me and my friend.

Why can't I understand i can't be with you,

But didn't you love me too,

My heart is empty,

And I dont know what to do,

I hear a song that reminds me of you,

I remember that we are through,

My love for you has gone away,

But the face of you still remains,

So I hope my heart will mend,

But until then I hope you understand.