For as long as I can remember, I have been a fan.

A fan of what isn't important. The issue is how. Most people enjoy books, movies, music and so forth in the course of their lives. But I have made the course of my life enjoying books, movies, music and so forth. I have paid more than $100 for a single compact disk. I have stood outside movie theaters for six hours in heavy rain and bitter cold. When I woke up at 3 a.m. one morning to find my apartment filled with smoke, the only thing I grabbed on my way to the fire escape was a paperback that had been out of print for 40 years. I don't recall putting on shoes.

I wasn't alone in that life, but I never knew it. If you liked something so big that it had an organized fan base -- "Star Trek," say, or the Beatles -- there was a network of people to turn to. Otherwise, there was simply no public venue for your enthusiasm. You couldn't go someplace to check if anybody else shared your devotion to, say, the Little River Band or Gerry Rafferty. Once in a great while, you might flip to the back pages of a record-collector magazine and find a half-inch blurb for a convention at the Sioux City Days Inn, or subscription information for a newsletter some guy ran off on the mimeograph machine at his mother's office. Apart from that, you found a couple of friends who would put up with your ranting about the infamous "lost" Steely Dan song "Second Arrangement," and that was that.

After a few years, that kind of life will bring on some serious four-o'clock-in-the-morning questions. Why do you care so much? Why can't you just read a book or listen to a record and let it go? Without the assurance that somebody else is just as crazy as you are, you start to visualize the years ahead with mounting horror: pawing through used-book stores; haunting record shops on Tuesdays, waiting for the new releases; deconstructing "The Wreck of the Edmund Fitzgerald" to the delight of none.

Then the Internet turned everything upside down. Or, rather, inside out.

Simply put, the private world of the enthusiast -- which is to say, nuts like me -- is now public. The Internet offered fans the forum they never had, and they jumped at the chance to thrust their obsessions out into the world. Ambitious heads set up newsgroups, mailing lists and Web sites to create a central clearinghouse for information and to connect with other people who share their passions. It's the ultimate validation of obsessive fandom: Go online and you'll find that not only are you not alone, you're jammed cheek to jowl with other people who know all the words to the "Land of the Lost" theme song and won't rest until they can do a little Lacanian analysis. Why do you care so much? Take a look out there -- who doesn't?

I have mixed feelings about this new state of affairs. On the one hand, it's hard not to get excited about the sheer volume of stuff that's finally available. But part of me is concerned about the long-term implications of putting fandom on display. If you drag people's deep-seated passions into the light of day, you're bound to pull up some pretty ugly stuff, too -- and I think that's already begun to happen online.

First, though, the highlights -- because, for now, they do outweigh the bad. While fan sites aren't going to save the world (only online retailing can do that), they have made possible a big change in how we relate to the stuff we love. The sites let us take a deeper look at work and people that make life interesting -- scrutiny that simply wouldn't be possible otherwise. In a sense, by putting years of research and introspection online, the fans have turned the Internet into a kind of collective biography of popular culture. And the importance of that can't be overstated.

Look at it this way. If the Internet went away tomorrow, you wouldn't lose the ability to find out about the Treaty of Versailles. You could walk into any bookstore or library and find all the information you need on the major figures and events in world history, from Washington to Ellington. But move outside that circle, or even move to one of the less-traveled spots on the circumference, and the reference materials start to dry up. You're left with occasional articles in newspapers and magazines, maybe a biography that goes out of print in five minutes.

In other words, things only a die-hard would track down and only a squirreler would save. For years, if you cared enough to do that, you had to wonder about your relationship to reality. Now, by creating a Web site, you can become an amateur scholar and historian, sharing years of research, accumulation and introspection without vetting from official channels.

This is a remarkable situation, whether you're a die-hard or a dabbler. Here's a simple example: the Byrds. A couple of years ago, I decided I didn't know enough about the band. Maybe I heard a song on the radio; maybe I saw a blurb in a magazine; maybe a friend mentioned them to me. Common enough, right? Whatever sparked my interest, I decided to go online and do some research. With a few seconds' surfing, I was at Byrdwatcher (http://ebni.com/byrds/), which broke the band's history down by album and provided juicy miscellany in the margins. A few clicks deeper into the site brought another trove of information, ranging from discographies to lists of band members' solo projects and artists influenced by the group. In about 10 minutes, I went from knowing absolutely nothing about the band to having a solid background -- and wanting to buy everything they'd ever recorded.

Now, let's go back to the beginning of that anecdote -- I'm interested in the Byrds -- but remove the Internet. Where do I go? The bibliography on Byrdwatcher consists of books and articles compiled over decades. Some people (if they were somehow able to get the bibliography) would be curious or obsessive enough to track down that information; maybe I would've, too, back when I spent every free minute hanging out in record and book stores avoiding honest work. Most people wouldn't go to those lengths, though, and the interest would wither. The same holds true for most devoted fans who want to know more about their object of adoration. Even if you've got all the Byrds albums on lovingly preserved vinyl, no aficionado is sharp enough to catch every article that comes out, or has enough cash to throw around to buy the deluxe CD reissue series with exhaustive liner notes.

What's more, the Byrds represent the easy stuff, having been relatively well documented over the years. Internet fandom's real value lies in the history of things that have never been recorded, and never would be recorded otherwise. The examples I'm going to give will, inevitably, look ridiculous and esoteric. But that's precisely the point. Everybody's got crazy interests they couldn't possibly explain to anybody else -- yes, even you -- and the Internet allows this cultural ephemera to be preserved when official memory does not.

I stopped being shocked about what's out there when a friend told me to type goldmonkey.com into my browser. I was rewarded with an exhaustive guide to the short-lived and largely unlamented TV series "Tales of the Gold Monkey." Another site, which appeared to be down for construction at the time of this writing, contained one of the greatest labors of niche love I've ever seen: an in-depth timeline of the "Planet of the Apes" universe, spanning several thousand years and culling dates from not only the movies but also such obscure sources as the "Apes" TV and comic-book series. If those seem a little frivolous, consider the Compleat Bellairs site (http://www.compleatbellairs.com/), devoted to the works of the late author John Bellairs, who wrote pioneering gothic-suspense novels targeted to young-adult readers but followed cultishly by grown-ups, too.

But the fans aren't the only ones writing biography out there -- a good number of writers, musicians, actors and athletes have set up outposts online. Some offer little more than news, such as concert dates or future releases. Other artists go further, however, and take advantage of the commercial, and connective, powers of the medium. Many are selling their work online, bypassing middlemen and appealing directly to the fan base -- which allows them to release work that might not find a home at a major distributor. And some artists are galvanizing their fan base even further by starting mailing lists, offering online diaries and responding to e-mail from their audience, a level of contact that simply wasn't possible in the past.

It's quite a picture. Not only can fans recognize each other, but they also can be recognized by the people they admire (and sometimes rewarded with tickets, Web-only releases and other exclusive deals). And maybe, in the process, they've created a new way of looking at popular culture.

Yet, every so often, I find myself feeling concerned about the future of the whole thing. It comes down to a very simple fact: There are bad fans out there as well as good ones, and the bad ones are much louder and much more visible.

Fandom, if you haven't guessed by now, has an unpleasant side: excess. Fans spend too much money and too much thought on the things they love. At best, aficionados take their passions, and themselves, with a grain of salt; they don't love any less, they just try to do so with some brains and humor as well as heart. At worst, though, all that fans offer the world is empty fetishizing and inarticulate enthusiasm. Maybe the guy who wears a "Star Trek" outfit in public, and argues about the show's made-up science with the ferocity of a prosecuting attorney, is composing learned treatises in his head. Maybe the gent who spends an entire concert screaming out the title of His Favorite Song harbors a sensitive soul beneath his 30-year-old T-shirt. But I doubt it.

All fans have that monomaniacal obsessive lurking inside them. If they didn't, let's face it, they wouldn't be fans. But the unreasonable ones show the world nothing but that obsessive -- which poisons the well for fans who know how to modulate their passions. Seeing the guys in the "Star Trek" suits, or the screaming loners at concerts, makes the world at large suspect that all fans are nuts, making it hard for any aficionado to come out of the closet. Even worse, those guys make fans think that all fans are nuts. So, reasonable enthusiasts back away from their passion, or subject themselves to intense self-scrutiny, before they end up like that guy in the corner who wants to be called "Scotty."

What does this all have to do with cyberspace? I'm afraid that the same dynamic that takes place in the real world, with loopy fans driving out sane ones, will happen online.

For every site that is a reasoned, comprehensive attempt to articulate a passion, there's another that is little more than a billboard announcing an obsession -- "I'm Teddy, and here's some stuff I dig!" -- with no content, no research, no insight, no attempt to reach out to the world or even other fans. Then there's the level of dialogue. I've been a part of lots of focused, enthusiastic and polite discussions in forums and mailing lists. But in some spots the conversation is so debased that it makes the very impulse to enthusiasm feel tawdry. I've seen personal attacks on the artist being discussed, as well as other contributors to the discussion; idiot debates over minutiae; and an overall lack of reasonable thought, clear expression and self-awareness. If the good sites are a living answer to Why do you care so much?, the bad ones aren't even dimly aware of the question.

Doing this kind of stuff in cyberspace hurts fandom just as much as it does in real life. Every asinine site and dopey debate damages the credibility of the reasonable ones, both with the world at large and with fans themselves. Creating and maintaining a worthy site takes a lot of work. Why reach out across cyberspace if the rest of the online crowd is reaching back with, "I'm Teddy, and here's some stuff I dig!"

Maybe I'm being a worrywart; maybe I'm being a snob. But I can't help but think that all of the good stuff we've got might go away as quickly as it came -- and as unlamented as the art it celebrates. I can easily see a time when the current generation of Web-site creators decides it's just not worth the effort to continue and packs its virtual bags. Maybe they won't even be disgusted with the environment; maybe they'll just have more pressing concerns, like families or work. And who'll take their place? Teddy? I'd be as happy as anyone if the idiots swarming onto the Web mature into responsible custodians. I just don't have high hopes it'll happen.

I'll make a deal with you, all you good fans out there. If it falls apart, we'll meet once a week at my place and shoot the breeze about Roger McGuinn, "Second Arrangement" and "Life, Liberty and Pursuit on the Planet of the Apes."

Just ring the bell. If I'm not home, I'll be in the bookstore down the street.