sad? No, I am not.. but y?

A friend of my friend passed away. I knew it when I read my friend's blog. At first I felt nothing, just thanks God that she is already a Christian. But then, the news and invitations to her funeral ceremony is all over the facebook. Only now I realized, I do not feel sad for her? Do I really have feelings? Do I really care about others ?  Current mood *S.A.D* sad because I felt nothing about that person.. 2nite, I was a little bit stress... dunno why :( It is scary when people do not feel sympathy, how to become a doctor if your heart is as hard as a stone?