If you were an immortal, as in you couldn't get sick or die, surely, eventually, you'd slide into complete boredom after having done and seen absolutely everything there is to offer? Presumably, this is one of the downsides to being a vampire, well, that and the need to murder the living in order to drink their lifeblood. One way a vampire might be able to stave off boredom is to throw a big party for all their friends. Even if the vampire in question doesn't end up having a good time, they can at least drag others down to their level of catatonic despair. Oh, the joy.