I've given more thought to the subject matter of my previous post on geek culture, and I've come up with an answer which seems so obvious that I don't know why it didn't occur to me before.
Intense interest in a subject or an activity can't make you geek. You also have to be part of the subculture. And everyone knows being part of a subculture is more than taking an interest in certain subjects. It also means socializing with other people who are interested in that subject, going to organized events, joining internet communities devoted to the discussion of the subject, and in many cases wearing the clothes and adopting the manners of speech and expression of other members in the group.
That being the case, I am definitely not a geek. I have no problem with geeks per se, and I have plenty of geek interests. I'm just not comfortable with subcultures in general. While I understand it's second-nature for some people to identify themselves through inclusion in a group (or through their choice in friends), I'm rarely comfortable with that, even if the group in question is marginal or non-conformist with respect to the rest of society. Sure, I have a certain "look" to me which is premeditated (along with distinctive tastes in music, movies, and books), but it wouldn't mark me for inclusion in a group. All my friends are pretty different from one another, and it's usually strange having even two of them in the same room together.
By contrast geeks are inherently social. It seems like an odd thing to say, given the stereotype of the geek staying home Friday night to play World of Warcraft. But while geeks may sometimes not fit into mainstream culture, there's never a shortage of other people who are into roleplaying, genre fiction, cosplay, anime, or programming. On the contrary, some of these are multi-billion dollar markets. There are so many people interested in some of these things that if you want you can choose only to socialize with people who are interested in them. Of course, that's when you get the "I'm different—just like my friends!" mindset, where folks within a subculture tend to have the same cultural references (quoting lines from Monty Python or The Big Lebowski or xkcd), a lot of the same mannerisms, style of dress and music (in the case of hipsters). (That's one of the main reasons I'm not comfortable with it.)
The majority of people seem to have a strong social instinct. They form groups with an inside/outside structure that set requirements on who can belong and who cannot. They form an understanding of who they are by means of their inclusion in the group, so that the group is more than the sum of its parts but also validates the individual's form of life. (This is what Hegel called "spirit" [Geist].) The expectations of the group are norms internal to each member, guiding, restricting, and validating action on a subliminal level. If Freud is right on this point (and in general I think he is), then this is not particular to subcultures but to human civilization generally, so I don't mean to this last point in a disparaging way.
Though the irony of subcultures is that the members really do think they're somehow being more individual by being part of the subculture. For an individual who spent a chunk of their adolescence feeling like a weirdo, the feeling of relief is real when you finally find people who have similar interests as you and who you can "be yourself" around. But if there are so many other people who turn out to be pretty much the same as you—with the same cultural references, mannerisms, etc.—how much are you "being yourself" anyway? The unasked question behind all subcultures is: Who is the me that is me? Why are you you? Is there something to me besides these patterns of behavior and outward appearance? Or am I just an accumulation of causes and effects? Maybe it's because I've always been interested in questions like that that I've never allowed myself to sink into a subculture.