I want to focus on the social power this individual had, and to remind everyone that interested people are interesting
The reason that you're friend was so magnetic was because they could look at an old tattered map, be entertained for an hour, and be open to sharing that experience with those around them.
Or as happened in this map genius story, if they're charismatic enough to convince you (and the gathering crowd) that it's interesting. Professor sounds like an ideal place for that skillset to end up.
I know people who are profoundly interested in certain things but you learn not to touch the topic because they'll deep dive on something you don't care about, and they aren't socially skilled enough to keep you engaged despite that.
Yeah - unfortunately - this is not a story of a genius. It’s a story of someone who was interested in mundane things. I think it’s also important to realize that there were likely other attributes at play but OP likely has created a narrative that it was simply their interests that made them engaging. (This is usually not it - I’ve met plenty of people who were also interested in mundane things but exceptionally unpleasant to be around)
The reason that you're friend was so magnetic was because they could look at an old tattered map, be entertained for an hour, and be open to sharing that experience with those around them.