Dracula lends itself to this sort of thing because Stoker wrote a four-hundred page Rorschach blot. The master stroke of the novel is that we barely ever see Count Dracula at all. Again, like the damn shark in Jaws, he only pops up when it is time to feed. But we feel him. His presence saturates every page. And these days, when people keep going on about Gone Girl and the novel's use of the unreliable narrator, it is useful to point out this is exactly what made Dracula work. The novel is told through diary entries and newspaper clippings, and half the time the narrators are writing about things they don't understand the significance of. Stoker's book is the equivalent of rounding up witnesses to a crime...each of whom gives a slightly different account. It is so easy to reinterpret Dracula because none of the book is admissible in court. Every word of it is hearsay.
What does Dracula look like? Old? Young? Is he clean-shaven or does he have a pointy black beard? What is he doing in London, really? Does he kill Lucy or is it that quack Van Helsing, who is a "devout Catholic" despite having no problems desecrating the Host, is a "polymath linguist" who can barely speak English, and gives his patient dozens of transfusions from multiple donors despite not knowing the first fucking thing about blood types? This is why there have been 170 film versions, countless TV appearances, and hundreds of literary retellings. Because we don't know any of the answers. Alongside Jack the Ripper, the Count remains Victorian England's grisliest unsolved mystery.
We don't even know if he is dead. After painstaking reams of vampire lore are poured on us by Van Helsing, all telling us how difficult Dracula will be to kill and how he needs to be staked in his grave, his head cut off and mouth stuffed with garlic before burning the body...he is dispatched by getting stabbed with a knife. Maybe. At sunset his body vanishes into a cloud of dust, and the vampire hunters celebrate. But Van Helsing told us the vampire can shapeshift at sunset, midnight, or sunrise (not at will as in the movies), and witnesses have already seen the Count turn into motes of dust before. Has Van Helsing suddenly acquired Alzheimer's and forgotten all his lore? Have they all?
It is these cracks, these plot holes, that Dracula achieves greatness, because everyone fills them in differently. It is why we can keep going back to it. While each retelling seizes a shadow of the story and rides it, the original is a whirlwind of uncertainty. And nothing scares like the unknown.