This is good advice, and my response is also going to sound terribly arrogant. But I also terribly do not care: I am only interested in deep friendships with people who can keep up with me intellectually and unfortunately that’s a really small slice of the population. And it is very difficult to find this cut of people I could be friends with, especially as even the “very smart” usually aren’t all that bright in reality.
I don’t need my friends to know the disparate things I’m aware of or be involved in all the weirdo crap I like. Frankly, I don’t think anyone can know all of what I do because you have to read dozens of books a week for a couple dozen years to do that. And not many can or probably should undertake such a project. And, just so there’s no misunderstanding, I do not need these friends to agree with me.
But I do need people who don’t have brain stall-outs out when I talk about Noether’s Theorem or describe the philosophical milieu of early 20th Century Germany or whatever crap I’m going on some too-lengthy spiel about.
These things both will not be interesting to most people and their brains can’t hold them enough to have any sort of conversation, either.
I tried to be a polymath. It worked a bit, but it can also be lonely. That said, I am what I am, for better or worse. I’m happy, too. But there are maybe a few score thousand people like me around the world and they are very hard to find in all the din and distraction.