Lack of Tear

I always wonder if I am cold blooded or I just feel sorrow slower than other people or it takes more for me to feel anything. Last night, I went to a prayer meeting with my friends and we were praying for Pastor Chan's tragedy. All the girls started crying but I didn't. I feel kind of bad not crying and kind of feel that I should. I always feel pressure when I see people crying but I don't have any tear. I remember when I attended my grandfather's funeral, I didn't cry until I saw my mom crying, then it hit me. Even hearing my grandmother's death, I didn't feel anything until several days later. May be I was just slow. But I don't know if I dry up all my tears in the beginning of the year already. Like I told my friends, I probably use up all my crying portion. I lost my ability to cry anymore. Or I am just a more cold blooded person. My friends were asking why this happen. Why would God let this to happen? I am actually quite surprised at myself that I actually have no problem rationalize the whole incident. A friend said it could be the Spirit lead me. I don't know. May be I really lost touch with everything and can't feel anything anymore.