If I was 15 years younger I would print a rofl emoticon.
movies? You get your idea of what a vampire is from movies?
There are http://nl.wikipedia.org/wiki/Anne_Rice http://en.wikipedia.org/wiki/I_Am_Legend_%28novel%29 http://en.wikipedia.org/wiki/Dracula books out there.
A movie by definition cannot do justice to vampirism, as it is action packed, has to drive onward, it has no time to go into lore.
I said books earlier
Because vampires are genetically altered by Clavicus Vile. While they may act like our real life folklore vampires, Bethesda added a twist to them, as most of their things are given.
For example, werewolves are suppose to transform every full moon, yet the members of the Circle are altered by a pact made by the Witches of Glenmoril.
Vampires of Cyrodiil are altered by Clavicus Vile. And Clavicus Vile always demands a price. And that is the price, backwards feeding. If a vampire wants to blend in, they must feed. But they lose their greater power. And if they want that greater power, they will lose their mortal appearance, and their weakness to fire and the sun will increase. You cannot have one without the other.
Oh ok so it even says it is backwards feeding and people know this ingame and outgame like here? I was trying to get across how backwards it was and it just seemed like no one ever got into vampire lore untill they got Oblivion or Skyrim :/
Shame on Bethesda for not just copying/pasting vamps from other media! How DARE they make their own spin on it!
Shame on you for just following what Beth says and not questioning it

Okay, but where is the inspiration for vampires becoming weaker after feeding? I'm fine with them using blood to blend in and appear human, but obtaining powers because they haven't fed seems weird to me.
That is what I want to know but sadly it will more or likley be explained by "its their game, they made it up blah blah blah deal with it" type of reply unlike real answers and we all know the lore W&V BUT some people want better answers cuz thats just like saying "it was in their brain"