While we were busy celebrating America's birthday, another anniversary snuck by us: on July 5th, Seinfeld turned 25 years old. And despite being old enough to drink, smoke, and drive a rental car, the show is still a nearly-universal cultural reference. The one-hour documentary Seinfeld: How it Began is required watching for any die-hard fan.

It's uncanny: turn on any TV connected to any cable service, any time of day or night, anywhere in the U.S. (and probably the world). With enough channel surfing, you're bound to find a syndicated re-re-re-re-re-re-rerun of a Seinfeld episode. The theme song alone has snuck into our collective subconscious. I'm betting you can recognize it immediately, from three rooms away, whenever it pops on the TV.

Is there anything else that debuted in 1989, and stopped being updated in 1998, that has a similar cultural universality? I can't think of any. The number one song on the U.S. Billboard charts the week that Seinfeld debuted is recognizable, I guess, if you've got a penchant for slightly dusty old tunes.

Even some of the best TV shows that debuted alongside Seinfeld feel like cultural footnotes or kitschy throwbacks today. American Gladiators? Doogie Howser, M.D.? Great shows, to be sure—but you'll have to look long and hard in the weird corners of your set-top-box to find reruns of either one.

There's one other show from the Class of 1989 that seems to have the same staying power: The Simpsons, which would debut in December of that year. Both shows had that magic recipe of jokes and gags that never seem to get old, even if the plot details would be rendered largely irrelevant by the inclusion of modern tech.

So tonight, sit back and learn the backstory behind the greatest sitcom that was ever written about nothing. Yes, if you're a fan, you've probably seen Seinfeld: How it Began a million times. But where Seinfeld's concerned, that never seems to stop us.