Whether you're a fan who only recently caught Seinfeld fever or a Seinfeld devotee, a fan who's seen each episode at least a dozen times, who quotes Seinfeld dialogue liberally, and who describes everyday life occurrences as "it's like that Seinfeld episode…" we feel confident that you'll find something surprising in this round-up of show facts. So happy 25th anniversary, Seinfeld… we celebrate your greatness with a whole lot of somethings about the "show about nothing."

1. British actor Norman Brenner was the stand-in for Michael Richards for all nine seasons of Seinfeld, but he also played an extra in more than two dozen episodes. One of his most memorable extra spots (that is, one where his character had a name and was not referred to as "Man in Store," "Man on Sidewalk," or "Man on Bus"): as Ian, a friend of Elaine's shady clothing salesman boyfriend in Season 7's "The Wig Master." Brenner was such a beloved member of the show's staff that he also had a role in the 2009 Curb Your Enthusiasm episode "Seinfeld" that featured the Seinfeld reunion (he played a customer at Mocha Joe's coffee cart).

2. In Season 8's "The Pothole," Jerry's girlfriend's toothbrush falls into the toilet, and she uses it before he can tell her. Like so many Seinfeld plots, the toothbrush debacle was inspired by the real-life experience of the episode's writer, in this case, Dan O'Keefe. O'Keefe's then girlfriend, now wife, used her toothbrush before he could tell her it had fallen into the toilet, too. And when asked if she had yet forgiven him for it, he revealed: She still doesn't know the truth about the episode's origins. Well, until now.

3. Jerry Seinfeld's fascination with the number nine factored into his decision to end Seinfeld after — yes — nine seasons. From a 1998 Vanity Fair cover story that coincided with the series finale:

Jerry Seinfeld loves the number nine. It is significant to him, an auspicious number. He was born in '54 (5+4=9), graduated from high school in '72 (7+2=9), first appeared on The Tonight Show in '81 (8+1=9), and Seinfeld premiered in 1989 (1+9+8+9=27; 2+7=9). His show comes on at 9 p.m., and this, the last season of "Seinfeld," will be the ninth. It will end in 1998, which, again, equals 27, and yes, 2 plus 7 equals 9. "Nine is cool," Seinfeld says gleefully. "By the end, we will have done 180 shows (1+8=9). When I was thinking about quitting the show, I thought, nine. People said, '10 — why not 10?' But 10 is lame. Nine is my number. And then I found out that nine in numerology means completion."

Jason Alexander as George Costanza More

4. Jason Alexander's wardrobe for George Costanza was often made one size too small, which added to the portrait of George as perpetually annoyed.

[Related: 7 Reasons to Watch Jerry Seinfeld's 'Comedians in Cars Getting Coffee']

5. Seinfeld had its controversies, but the most controversial episode was the one that turned off the cast so much they didn't even film it. "We had a script that the actors and I started to work on and none of us liked it," director Cherones says. "It was about a gun, and guns aren't funny. I went back to the office that first day, after we were sent down to rehearse, and said, 'We don't want to do this one.' And Larry and the Castle Rock executives whom we talked to all agreed, and Larry wrote another script." Season 2's "The Bet" revolved around Elaine and Jerry making a wager about how easy it would be to buy a gun. When the script was tossed out, it was replaced with "The Phone Message."

6. Seinfeld inspired a pair of rap albums. Wale's 2008 The Mixtape About Nothing features tunes like "The Kramer" and "The Vacation From Ourselves," which includes a guest appearance by Julia Louis-Dreyfus. More About Nothing, a follow-up, was released in 2010, and this fall, Wale — who says he's seen every Seinfeld episode multiple times — will release The Album About Nothing, a CD he worked on with… Jerry Seinfeld. Seinfeld also recorded "The Outro About Nothing" for Wale's 2013 album The Gifted.

See Wale in the studio with Seinfeld:

7. Kenny Kramer, Larry David's real-life former neighbor, says he was paid just $1,000 to allow the series to use his name for the character of TV Jerry's neighbor. Real Kramer has profited from his association with the show, however, and continues to do so as the proprietor of the Kramer Reality Tour, a Seinfeld-centric bus ride through New York City that, more than 15 years after the series finale, still sells out.

View photos Kenny Kramer during 'Kramer's Reality Tour' More

View photos Jason Alexander as George Costanza and Marisa Tomei as Herself in 'Seinfeld' More

8. George's obsession with Marisa Tomei? Sure, he thought she was beautiful, but Tomei says the real reason she was the celeb object of Costanza affection was because the Seinfeld gang liked the sound of her name. "They just called and asked if I wanted to, you know, come and be a guest on their show," Tomei said in an NPR interview. "And then later I said, 'Well, why did you even choose me?' And they just said, 'We like the rhythm of your name.' It really had nothing to do with me. 'We like saying your name, Marisa Tomei.'"

9. In the Season 6 episode "The Race," the coach who oversees Jerry and Duncan's rematch is Mr. Bevilacqua, whose name is a shout-out to Al Bevilacqua, a wrestling coach and gym teacher at the real Jerry Seinfeld's alma mater, Massapequa High School on Long Island. Seinfeld's fellow Massapequa High alums include Grammy-winning musician Brian Setzer, Emmy-winning director Tim Van Patten, Golden Globe-winning screenwriter and Vietnam War veteran Ron Kovic, and public scandal stars Jessica Hahn and Joey and Mary Jo Buttafuoco.

Related: Jerry Seinfeld's Blunt Take on Diversity in Comedy: 'Who Cares?'

10. Michael Richards makes his first sliding Kramer entrance in Episode 3, "The Robbery." He did it another 284 times by series' end.

Watch a compliation of Kramer's entrances:

11. In 180 episodes, Seinfeld had just seven directors, with Tom Cherones and Andy Ackerman at the helm the most: 81 times for Cherones and 87 for Ackerman. Jason Alexander is the only cast member to direct an episode of the show (Season 3's "The Good Samaritan").

12. In the Season 5 episode "The Lip Reader," Big Brother Season 7 winner Mike "Boogie" Malin plays a tennis ball boy in the beginning of the episode and during Kramer's ball boy tryout.

[Related: Julia Louis-Dreyfus Talks About Her 'Fun' TV Career at Television Academy Hall of Fame Induction]

13. Seinfeld has been spoofed on Freakazoid!, Muppets Tonight, Family Guy, In Living Color, Funny or Die, and, in a hilarious but NSFW Saturday Night Live episode, Oz. Oh, and porn, which, again, NSFW.

View photos Lee Garlington as Claire in the 'Seinfeld' pilot More

14. Lee Garlington, the actress who played waitress Claire in the pilot, was originally going to be a regular cast member, but when the show was ordered to series, the character was no longer part of the landscape. According to Jason Alexander during a 2010 interview on Kevin Pollak's Chat Show, Garlington made the crucial error of telling Larry David she had "a few ideas" about the show, and, yada, yada, yada, Claire the waitress was replaced with Elaine the Benes in Episode 2.

15. Alt-casting: David Letterman bandleader Paul Schaffer, Nathan Lane, Steve Buscemi, and David Alan Grier were considered for the role of George; Patricia Heaton, Susie Essman, Megan Mullally and Rosie O'Donnell were considered for the role of Elaine; and Tony Shalhoub and Larry Hankin were considered for the role of Kramer. Hankin is the actor who played Tom Pepper, the actor auditioning to play Kramer, in the Season 4 finale "The Pilot."

16. In a May 2012 episode of Watch What Happens: Live, Jerry Seinfeld named "The Alternate Side" his least favorite Seinfeld episode. His top five: "The Boyfriend," "The Contest," "The Pothole," "The Rye," and "The Yada Yada."

17. The J. Peterman Company, Elaine's employer, is still in business, despite some post-Seinfeld financial difficulties. And John O'Hurley, who played TV Peterman, sits on the company's board.

18. For $50 you can purchase a remarkably accurate facsimile of the titular, piratelike garment from "The Puffy Shirt." One of the shirts used in the episode sold for $16,500 at a 2002 auction, while another is in the Smithsonian.

19. In "The Jacket," we meet Elaine's intimidating papa, writer Alton Benes. The character was inspired by Revolutionary Road novelist Richard Yates, whose daughter Monica dated Larry David. The actor who played the gruff Mr. Benes, Lawrence Tierney, was just as frightening in real life: He took a knife from the set, which freaked the cast and crew out so much they abandoned plans for a return visit from Elaine's daddy.

20. Kenny Rogers Roasters gave the series permission to use the restaurant in Season 8's "The Chicken Roaster" and even provided a meal to the cast and crew. Country legend Rogers's restaurant chain has since gone out of business in the United States but is thriving in parts of Asia, where the menu includes items like Beef Bolognaise Spaghetti, Tangy Chicken Spaghetti, Chocolate Raisin Muffins, Muffin Submarines, and Egg'cellent Sandwiches.

View photos Michael Richards as Cosmo Kramer and Wayne Knight as Newman in 'Seinfeld' More

21. Frank Sinatra died during the West Coast airing of the Seinfeld finale on May 14, 1998. An ambulance arrived at Sinatra's home in just four minutes, and the Los Angeles fire chief said it was because there was little traffic on the streets: Everyone was home watching Seinfeld.

22. The Season 4 episode "The Virgin" was co-written by those Farrellys, Dumb & Dumber brothers Peter and Bobby. The Farrellys had another Seinfeld-related experience in 2012, when Larry David played a nun in their big-screen Three Stooges movie.

Video: It's a 'Seinfeld' Reunion! Watch Jerry and George Bicker Over Super Bowl Etiquette

23. Bored and annoyed partygoer Elaine shuts down an obnoxious fellow guest in "The Stranded," when she refers to the movie A Cry in the Dark and tells the woman, "Maybe the dingo ate your baby." The 1988 movie is based on the real-life 1980 case of Michael and Lindy Chamberlain, who said their 9-week-old daughter Azaria had been taken by a dingo while they were camping in the Australian Outback. Lindy Chamberlain was put on trial for the murder of her child, and spent three years in prison before being set free after a retrial. In 2012, after another inquiry into the baby's death, a coroner officially declared little Azaria had been taken and killed by a dingo (a wild dog). "The Stranded" is also notable for a guest appearance by the pre-The Shield Michael Chiklis.

24. In 1998 Seinfeld received an award from the American Academy of Dermatology for "The Slicer," the Season 9 episode that, according to the AAD, promoted skin care awareness. The episode featured Melrose Place and Desperate Housewives star Marcia Cross as dermatologist Dr. Sidarides, or, as Jerry referred to her, "Pimple Popper, M.D."

View photos

25. Despite the plethora of memorable supporting characters on Seinfeld, the only one who came close to starring in his own spinoff series was Phil Morris's Jackie Chiles, the attorney who never fared well in his representation of Kramer. Morris says nearly everyone involved with Seinfeld had given a thumbs-up to the spinoff, but a "business affairs kerfuffle" ultimately did in what could have been his Frasier.

Though he didn't live on in primetime on a weekly basis, Jackie Chiles — who was inspired by O.J. Simpson trial attorney Johnnie Cochran — has continued to pop up in pop culture, including in an ad for Jim Beam and Funny or Die videos. P.S. Morris won the role of Chiles against competition from fellow actors like Ted Lange, Michael Dorn, and Michael Boatman, and he may have had a little advantage: Morris, his dad (the late Mission: Impossible star Greg Morris), and Cochran went to the same Los Angeles barber for years, which gave Morris lots of opportunities to observe the attorney and gather inspiration for his Jackie Chiles portrayal.