Humanity is a lie...
This is a fact that Vampires do not like to face: the human dies in the Embrace. The creature that is revived into Vampirism is not, in any fashion, human. A vampire is a savage predator, a solitary nocturnal hunter. The Beast is not an enemy or a dark evil force, but the instincts and essential drives of the Vampires new nature. The Humanity of the "Kindred' is a lie and a taint, the half-remembered impressions of a man that is now dead.
The lie is an easy one to keep, at least at first. The memories of life are still fresh, and the prey that you hunt have names and loved ones. Yet the Beast is always there, and the truth will make itself known no matter how it might be denied. Every Vampire remembers the first time he looked at a human and first saw not a living being but a tender morsel, though many would deny it. All know the fear that comes when he realizes that the concern he feels over former friends and loved ones is little more than a shadow of a living emotion. All know the sensation of emerging from a frenzy, not with horror, but with a slow realization that they have done something horribly wrong and should be horrified.
The realization creeps up on them, and they deny it, push it from their awareness. "I am still a Man," they say to themselves. "I am still the Man that I was." A part of them knows this is a lie, that their feelings and desires and goals are little more than a thin veneer over the burning hunger. That they are nothing but a savage bloodthirsty beast that remembers what it was to be a man.
The truth is this: The loss of that last shred of Humanity is not a loss at all. It is a realization. What is left is all that was ever there.