I can identify with the intellectual loneliness #6 that the article describes. Although, I don't think it has as much to do with your level of intelligence so much as simply being around people who don't know what you're talking about. I mean I enjoy a number of things that most people don't even care about, and it's not necessarily because they're stupid; they just don't care about what I care about. So I end up having no one to talk to about these things that interest me. I'm very independent-minded which has proven itself to be a blessing and a curse. Here are some of the things that interest me that I rarely have anyone to talk to about:
* Alternative medicine and natural health
* Computer programming / web development
* Drawing and art
* Reading non-fiction
* Writing diaries, poetry, etc.
* Playing old-school video games
* Playing tennis
* Staying up to date on politics
I don't know about others, but I have a hard time finding people who even have such a wide range of interests, let alone share mine. For the sake of socializing, I usually end up doing what other people find interesting while my own interests I have to pursue all by my lonesome.