It matters what you define as a vampire, the word vampire means basically blood sucker, and if a psycho maniac went around drinking peoples blood, then yes, he is a vampire, I believe in vampires, in fact, I believe in a lot of things, but I do not believe your friend saw a vampire if he watches a lot of television about the subject. P.S. Psychic vampires do not exist. For those of you out there that think you are one, there is always a nice, comfortable room at the nearest mental hospital near you.
The myth of vampires originated from Eastern Europe, because the earliest written records come from there ( Austro-Hungarian war diaries describe "vampiric" infection in some small secluted villages in Serbia , in Eastern Europe ), as well as the word itself.
But one thing is important to realize here, Vampires have never been considered physical creatures there. They were described as some sort of "ruber-y" ( baloon like ) human shaped shells that were caphable passing through walls, levitating or dissapearing suddenly. They were believed to have occasionaly drunk blood , from thei r, victms in order to keep the physical body in the grave fresh as long as possible. All of that indicates, what is later known as sone of the popular occult vampire theories, that vampires are Earthbound spirits of the dead, caphable of remaining in their Astral and/or Etheral husk ( body ) after their death. Degradation of physical body would probably cause degradation of Astral cord as well, and therfore, degradation of Astral body. That would explain why the blood had been essential to them. It is possible to "store liquids" in etheral form, as occultism teaches us ( Franz Bardon's works asexample )
so they could have carried blood in such form to their graves and their bodies.
But according to Eastern European folklore and mythology, another equally precious thing to them was energy , which they drew by means of biting or simple absorbtion, especialy of heavily frightened folk. It is more then likely that such energy helped them preserve their cadavers. Furthermore the "bites" would rarely be actual punctures, and even then, they were certainly not typical bite marks ( more like minute like-from-needle punctures ) and were most often in from of red stamps, much lile popular "hickey" or bruise, except they would not go purple or brown, as bruise is supposed to .
Now, it is alos crucial to realize, while we can not with certaincy claim the vampires firstly came to be in Eastern Europe, be it in myth, or reality, they are without any doubt European ! They do not come from ( allegdely ) blood sucking Egyptian dieties, Mesiootamian or Babylon deities, nor are they Lammias
one may encounter in Greek mythology !!! The only other place where they could have possibly been noted ( orally though ) is Ireland, where there was also class of undead spirits that sucked blood and energy. It could make sense for certain Celtic groups, from what we today know as Ireland at certain point inhabitated Eatern Europe and could have had at the poin t influece the native folklore . Also Dion Fortune in some of her works decribes almost exactly same entities, though coming from caertain Philipine tribes folklore.
Finally vampirism vas not contageous by bite... sometimes the drained victims, would go mentally ill, and after death could have become vampires themselves or hostile spirits of undead alike. So contagion by bite is a vast lie !
Another thing, Ann Rice writings, Twillight and Vampire diaries are simply not magickal texts/documnetary show. The depiction of vampire s in such pop - influeced art is overexagreated and presente d much like style of animated movies.
Other two, very real type of vampires are PSI vampires, or as clinical and bihevioral psychology calles them ( and studies from different perspetcive ) emotional vampires , who drain energy of others, or according to psychology cause others to feel emotionaly empty, sad or exausted.
The final version are Sanguinarine vampires, which are nothing more than humans ritualy drinking blood.
Therfore any living person claiming to be a vampire could only be one of the two lastly mentioned "classes" or type in a lack of better word.
Hope that this clarify s it bit for You. Blessings!