By now you should already know that geeks never merely enjoy something, they are in thrall to it. They don’t buy DVDs, they have a collection. They don’t just wonder what it would be like if Captain Kirk met Dumbledore, they write multi-part epic stories chronicling the event, and also work in an origin story for Darth Vader’s pants. Their interests are not merely their interests; their interests are their existence. Naturally, then, they are experts in their chosen fields.
The day after a geek-genre movie opens, you’ll find them in Internet forums and chatrooms discussing per-screen averages, star power revenue, sequel contract negotiations, and so forth. You won’t find them talking about whether or not it was any good, even though they were, of course, seeing it on opening night. In this situation the goal is not to discuss what you liked or didn’t like about the movie, but to show off all your knowledge of big Hollywood insider information. After all, having seen so many of these movies and read Box Office Mojo, you’re pretty much an expert on the business. (To be fair, a lot of the time this statistical regurgitation is intended to obscure the fact that the movie was a waste of celluloid.)
Left: Harvey Weinstein. Right: His exact equivalent.
Similarly, when a comics fan is tired of talking about how all comics suck and aren’t as good as they were when the geek was a kid, he’ll devour all the latest information on which Assistant Cover Editors got fired, who is in charge of Vertigo this week, and who is rumored to be sleeping with who in the industry. None of this can possibly have any bearing on the geek’s life, and he’ll go on hating the resulting comics no matter what the company’s org chart looks like, but he can’t imagine not caring about any of it. How can he say he likes comics if he doesn’t even know about the rights dispute on a bad girl book that hasn’t even released an issue in six years?
Part of this is because so many geeks would kill to get jobs in “the industry”, whatever that industry might be. Devoid of actual talent, they can at least fasten themselves to this information like a remora, and therefore give the impression that they’re pretty much up there with luminaries like Harry Knowles. It’s yet another example of the geek overimagining his role in the great scheme of things.
No level of knowledge is too small to keep the geek from being an expert, nor is any piece of information too trivial not to be latched onto. Give a geek a starting belt in karate and within minutes he’ll be explaining all the things Bruce Lee is doing wrong in this movie, while another geek is explaining that the foley work technique is typical of this particular studio.
In fact, the geek isn’t too shy to let a complete lack of knowledge stop him from opining on the industry, even to someone who actually works in it. Any given videogame playing geek will be more than happy to tell a game developer, should they encounter one, exactly how the industry should work. Nearly everyone who’s ever opened a pack of Magic cards is convinced that they’d be able to double Wizards of the Coast’s profits if they were in charge.
Knowledge is power, even if it’s stupid knowledge nobody cares about, so geeks LOVE casual expertise.
Stuff Geeks Love 
I feel you could gone for several posts about this subject alone. After all, in the age of Wikipedia, every geek is an expert on everything. A minimal effort isn’t even required anymore.
And God, you had to link to that review.
Well…I DID stay at a Holiday Inn once.
How is this unique to geeks though? I know way too many non-geeks who think they are experts on everything they’ve ever thought about for more than two minutes, and will argue this with an expert. For one, I’m a music composition major and constantly have to put up with random people I meet (who are not musicians) opine to me about “the state of modern music” or “what I should know about the music industry” blah blah blah. There was the time that a taxi driver, on finding out I was from Detroit, had to outline all his positions on the auto bailout to me to the extent of making me wait five extra minutes when we arrived at my destination. I think it’s just human nature to think one knows everything.
It’s funny that you chose to put a picture of Harvey Weinstein next to a geek, since both of them have about the same respect for women (though Weinstein’s stories of abusing Hollywood actresses are more shocking and outrageous. The worst a geek can do is rant about how some chick who’s out of his league won’t give him the time of day, which, yes, can be shocking and outrageous, but the Internet is chock full of that misogynistic crap and it gets tedious after awhile).