There is  always at least one person in every lifetime who will follow you like a fan only with the aim of tearing you down and trying his best to destroy you. Sometimes it is obvious who it is, sometimes it is not. One thing is for sure, that if your physical demise precedes his, you will find out who he is, and then you will have the option of haunting him through the rest of his lifetime. Should you do that, he will go around believing he is cursed. He will use all superstitious means to relieve himself of his burden, not knowing that he was, in the first place, the primary perpetrator.

This is the origin of all "curses", and is the reason why some people believe in curses and are under the impression that they are "cursed".