I am sorry you lost people in your life this way. Even though you are over it, maybe a part of you is not. Maybe its just a nervous thing, and not really a big deal that you do this, especially if it doesn't bother you much. Maybe you really care about the people in your life and don't want them to die. I cant tell you why. But if it's really bothering you maybe its worth exploring. Sorry for your distress. Sometimes we accidentally condition ourselves to act in certain ways. Like habits. I do it all the time.