Comic Strips

I thought it was an allegory for disease. Spreads person to person, water repels it and don't invite infected people into your house

Also garlic has antibiotic properties

It looks like both are true. Super people that are above normal ones, bleeding us dry just bc they can - nobility - and outright needing our work in order to sustain themselves, but also not needing people or thing on an individual basis at the same time, thus despite their need for us to continue their own existence not really caring much about us at all. The latter may have been added by Voltaire, but it forms a large part of our current understanding of vampires, and was a very natural extension.

Also the nobility could read, so had access to thousands of years of history, while a common peasant who could not read had to learn everything by themselves if they were not taught it by their village. Plus the former had access to healthcare and adequate nutrition thus lived far longer lives by comparison. So like if a "generation" might have been 10 years for a peasant, then a 60 year old noble would have been 6 generations past, enough for stories about them to be legendary in the villages, almost like they were immortal, plus their family history stretched back even further, long beyond the collective memory of the peasants as old by stories. And too those could start to blend together so like Richard III taking over after Richard II after Richard, stretching back hundreds of years.