I Genuinely Can’t Watch "The Big Bang Theory" The Same Way Again After Reading These 16 BTS Facts

Somehow, it's been 16 whole years since The Big Bang Theory premiered in September 2007. To celebrate the anniversary, here are 16 facts about the show that'll surprise you, educate you, and honestly just make you want to do another rewatch:

1.The character of Penny was originally going to be called Katie, and she wasn't going to be the "bubbly" version of the character we know now, but a much more cynical character. Kaley Cuoco auditioned for the role, but originally it went to Amanda Walsh, who even filmed the original unaired pilot in 2006.

Amanda Walsh playing Katie opposite Johnny Galecki in the unaired pilot

2.Marisa Tomei, Tara Reid, and Elizabeth Berkley also all read for the role of "Katie" (aka Penny) before she was ultimately immortalized by the one and only Kaley Cuoco.

Marisa, Tara, and Elizabeth from 2007

3.A long-discussed element of the show was that Penny never had a last name. The writers ultimately decided not to give her a surname before marriage because they got "superstitious" about it. Ultimately, her last name will always be her married name: Hofstadter.

Penny and Leonard in a scene from an early episode of the big bang theory

4.Penny wasn't the only role that could have looked super different — the role of Howard Wolowitz was actually originally written for Kevin Sussman (who ultimately played Stuart), but ABC wouldn't release him from his Ugly Betty contract in order to free him up to play the role.

Penny and Stuart in a scene on The Big Bang Theory season 2

"ABC had an option on Kevin and wouldn’t release him," casting director Ken Miller told Radloff. "And then the sad part is, he was never on Ugly Betty after that again. They kept him from getting that role on Big Bang."

CBS / Courtesy Everett Collection

5.The characters of Sheldon and Leonard were named after producer Sheldon Leonard, who produced shows like The Andy Griffith Show and The Dick Van Dyke Show.

A photo of producer Sheldon Leonard side by side with the characters of Leonard and Sheldon

6.And the character of Sheldon was inspired by a computer programmer whom Prady once worked with, noting that this programmer could "do amazing calculations in his head but couldn't manage to tip the waiters in a restaurant," according to NPR.

Sheldon on a computer during a Big Bang Theory scene

After Prady shared that story, NPR reported, Chuck Lorre said, "Hang on, I've never seen that guy on television."

CBS / Courtesy Everett Collection

7.The origin story of Sheldon's famous catchphrase "Bazinga!" is actually revealed in a 2018 episode of Young Sheldon. As a boy, Sheldon was trying to act more childlike and frivolous, which led him to a comic book store selling funny toys by a brand called Bazinga — and the rest was history.

Bazinga toy company from Young Sheldon

8.Young Sheldon also reveals that Amy and Sheldon eventually have a son together — and they name him Leonard.

Amy and Sheldon in bed together

9.Kunal Nayyar has naturally curly hair, so he straightened his hair for every episode to play Raj.

Raj and Howard in a scene in The Big Bang Theory

10.Carrie Fisher and James Earl Jones met for the first time appearing as guest stars on the show, despite their history starring in Star Wars.

Carrie Fisher, James Earl Jones, and Jim Parsons on The Big Bang Theory

11.Meanwhile, Mark Hamill was "a little nervous" at first to commit to appearing in the Season 11 finale to officiate Sheldon and Amy's wedding because the producers approached him as their "dream guest" without even having a script.

Mark Hamill on The Big Bang Theory

12.Mayim Bialik actually has a PhD in neuroscience in real life, and she has shared how it "came in handy" working on the show and how she would occasionally give small corrections to the scientific jargon in the dialogue. In fact, the writers even made Amy work in neuroscience as well because they figured it would make the character super accurate.

Mayim and Jim Parsons in a scene in the living room on The Big Bang Theory
CBS / Courtesy Everett Collection

13.Melissa Rauch revealed that the reason Bernadette's speaking voice was so high is that it was actually inspired by her mother in real life.

Bernadette and Howard in a scene

14."Soft Kitty" is such a big part of The Big Bang Theory, but CBS and Warner Bros. were actually sued over it. The suit was ultimately dropped.

Penny singing soft kitty to sheldon

15.As an act of solidarity, Jim Parsons, Johnny Galecki, Simon Helberg, Cuoco, and Nayyar each took a $100,000 pay cut from their notable $1 million–per–episode paychecks just before Season 11 to help elevate Bialik's and Rauch's salaries to over $425,000 per episode.

The Big Bang Theory cast at the People's Choice Awards
Steve Granitz / WireImage

16.Finally, the show wasn't always going to be called The Big Bang Theory — the original working title was Lenny, Penny, and Kenny.

Penny, Leonard, and Sheldon on The Big Bang Theory

The character of Sheldon was originally going to be named Kenny.

CBS / Courtesy Everett Collection