@Kuroww It's an interesting idea, and it's definitely helped by the notion that because they don't continue to age it's likely their brains won't deteriorate, but I dunno that vampires could become walking encyclopedias very easily. There are books I read in the past (whether it be 10 years or 5 or whenever) that even if I remember "I read that one before," it's not like I can recite every word. It's possible you could work to improve your memory with the amount of time an immortal lifespan provides if you really wanted to become some kind of legendary mountain sage, but most information leaves pretty quick if you don't need it or refresh it by testing yourself and stuff. And that's assuming you're vampirifying the most scholarly, focused human you can find. I don't think most of the people falling for high school gyaru vampire are committed lifelong learners lol.
Hell, as an example, I was studying networking and like IP subnetting shit as recently as 2016-2017, but once I
dropped out stopped needing it and bothering to remember it, it pretty much flew outta my head right away.