Someone can be one of those pain in the ass bores and suck like a Hoover factory… it’s not a XOR proposition.
It’s quite easy to get obsessive over the minutiae concerning a specific subject.
If the subject is considered esoteric it becomes a competition over who knows what about which minutiae. I know somebody, for example, who’s been working on her Ph.D in medieval history for nearly a decade. Her attention to detail can be painful if you’re not interested in the subject because she extracts details with the figurative fine gauge needle. If you pit her against another medieval historian they’ll argue the finer points of X until they both drop from exhaustion.
I see a lot of this in so-called “foodie” forums. eGullet was the granddaddy of such gastronomic intellect. Ever since they shut down people moved to Chowhound. I don’t even go there anymore because sometimes the conversation gets a leeetle too highbrow for my taste, especially when Top Chef is airing.