"Why should I," you may ask, "give a rat's ass about Watchmen?"

Granted, the movie has been seeping into mainstream pop culture since its numerous trailers started appearing on the Internet and in theaters around the country one year or so ago, and legions of critics consider Watchmen the "greatest graphic novel ever published." Hell, for what it's worth, it even made Time magazine's list of 100 Best Novels.

But Watchmen is primarily known to people who read graphic novels (aka comic books) on a regular basis.

Let me explain why the rest of you should care, too.

In 1986, before anyone ever thought about making a movie about it, Watchmen was published as a 12-issue limited series by DC Comics. (Years later, it was collected in one trade paperback.)

In the trailer for Watchmen, the storyline comes off like a big, bombastic science fiction epic. And it is … sort of. Peering past all the costumes and explosions and such, it's essentially a murder mystery that ultimately unfolds into a global conspiracy.

According to Wikipedia, the series — written by Alan Moore and drawn by Dave Gibbons (both from England) — "… takes place in an alternate history United States where the country is edging closer to a nuclear war with the Soviet Union, freelance costumed vigilantes have been outlawed and most costumed superheroes are in retirement or working for the government. The story [starring heroes with crazy names like Nite Owl, Dr. Manhattan, Rorschach, Silk Spectre, Ozymandias and The Comedian] focuses on the personal development and struggles of the protagonists as an investigation into the murder of a government-sponsored superhero pulls them out of retirement …"

That's pretty much the plot in a nutshell (ya gotta love Wikipedia), but there's so much more to Watchmen.

In the 1960s, Marvel Comics made superheroes more realistic with characters like the guilt-ridden Spider-Man. Decades later, Watchmen would up the ante by presenting superheroes who were not only emotionally scarred but in some cases psychologically disturbed. (For example, I think this was the first comic to feature a superhero who suffered from erectile dysfunction. Seriously.) More than any comic before, the series asked, "What would really be the social, financial and political ramifications if costumed heroes ran around fighting crime?" In one issue, for instance, it's revealed that the Superman-like hero Dr. Manhattan utilized his powers to win America's war in Vietnam, and that he's being used as a political weapon against the Soviets in the Cold War.

And Watchmen was also groundbreaking when it came to how it told the story. Swiping again from Wikipedia: "Creatively, the focus of Watchmen is on its structure. Gibbons used a nine-panel grid layout throughout the series and added recurring symbols such as a blood-stained smiley face. All but the last issue feature supplemental fictional documents that add to the series' backstory, and the narrative is intertwined with that of another story, a fictional pirate comic titled Tales of the Black Freighter, which one of the characters is reading."

So how did this history-making comic come together in the first place? As I previously mentioned, Watchmen was written by the British-born writer Alan Moore. A few years earlier, Moore had gained some popularity in America for revitalizing the down-right wack Swamp Thing for DC, and went on to write several other acclaimed comics. Initially, he'd wanted Watchmen to star a group of well-known characters DC had just purchased from a now-defunct comic company called Charlton Comics. But officials at DC, after getting wind of the full story, weren't willing to let him screw up heroes that cost them an ass-load of moolah. Moore was disappointed, but it didn't take him long to figure out that the story would work better with brand-new creations.

Unlike some great works of art, Watchmen was immediately appreciated by fans and critics alike. No one had ever seen such a mature depiction of superhero mythology. But it wasn't long before it influenced a whole new crop of creators — and not in a good way …

Some attempted to step up their game and make more challenging and artistic works. But most creators absorbed the more prurient elements in Watchmen, leading to a decade's worth of guys with mental problems who carried big guns and weren't afraid to blow a villain's brains out. That wasn't exactly what Moore was trying to do to the comic industry. In 2003, he said in an interview: "[T]o some degree there has been, in the 15 years since Watchmen, an awful lot of the comics field devoted to these grim, pessimistic, nasty, violent stories which kind of use Watchmen to validate what are, in effect, often just some very nasty stories …"

So what happened next? Well, good things and bad things …

Yes, Watchmen made DC a ton of cash, but Moore was under the impression that the rights of the series would revert back to him and Gibbons after a while. That was not the case. As a result, Moore felt swindled and vowed never to work for DC again. And he didn't … sort of. He created a line of books — called America's Best Comics — for a DC subsidiary called Wildstorm. While writing the ABC line, he created a series called The League of Extraordinary Gentlemen, which was later made into a sucky movie. (But the comic was great.) And while we're on the subject of movies, I should probably mention that Moore hates the idea of his comics being turned into films. He's a comic purist and creates work specifically for the medium. To that end, he hasn't made money off the films directly — he lets his collaborating artists (like Gibbons) take his own share of the proceeds.

Eventually, he stopped writing for the ABC line and for DC and all its subsidiaries for good. He currently does work for a small, indie publisher called Top Shelf.

Still, his influence on mainstream comics — and mainstream America — lives on. Several of his other comic works, such as V For Vendetta and From Hell, have been made into films. And a critically acclaimed writer by the name of Neil Gaiman (the guy behind comics such as Sandman, novels like American Gods and the current hit film Coraline) cites Moore as the sole reason he got into writing comics.

So, see: For good or ill, Watchmen is important. Only time will tell if the film affects regular moviegoers the same way it affected comic geeks (you know, like me). In the meantime, take my advice — go watch Watchmen.

Read Brian Ries' review of Watchmen.