Highlights

  • Some of the real life drama the cast dealt with made its way into episodes, like when Jim Parsons kissed co-star Mayim Bialik while he was sick.
  • Fans continue to love the show even after the finale, enjoying new behind-the-scenes tidbits that provide fresh perspectives.
  • Kevin Sussman and John Ross Bowie attempted side projects that were purchased but never developed, spotlighting the actors' endeavors.

The Big Bang Theory made audiences laugh (and sometimes cry) for 12 seasons. Each episode always built on the storyline but had moments that were unique to the episode in and of itself.

What fans of the show did not know was that behind the scenes, there were even more interesting and dramatic things unfolding than what was being written into the script. And sometimes, those bits of drama were just too good, and found their way onto the small screen.

Despite Big Bang Theory ending in 2019, fans still love the show and the characters. As such, new tidbits about what happened when cameras were not rolling have continued to come out over the years, much to fans' delight. And with the show continuing in syndication, learning new information about the characters or the actors themselves, sheds light on episodes that may make them be seen differently than they were in the past.

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Updated March 2024: Since 'The Big Bang Theory' ended, the members of the cast have all chosen different personal and career paths for themselves. Given the money made on the show and the reported $10 million from royalties from syndication, the main cast can choose the path they want to live for themselves without having to worry about money. And at the same time, fans can continue to enjoy their favorite show, especially when new Easter eggs are revealed about behind-the-scenes issues that occurred.

20 Jim Parsons Had The Flu During One Very Important Scene

The first time Amy and Sheldon kissed was when Jim Parsons had the flu

Jim Parsons And Mayim Bialik Were Uncomfortable With A Big Bang Theory Guest Actor Who Made A Scene Harder Than It Needed To Be
via CBS

Jim Parsons was sick during the worst time. During the fourth season of the series when Sheldon and Amy Farrah Fowler share their first kiss, Parsons was very sick. However, he kept working to get the scene done.

"You had the flu," Mayim Bialik said to Parsons.

"Ohhh," Parsons remembers. "You kept swishing around with Listerine or whatever to kill my germs."

"Hydrogen peroxide," Bialik stated. "You were sweating. You had a fever. You were very sick."

Parsons, who began acting like Sheldon stated, "I would not have kissed you."

"Oh, great. Thanks," Bialik replied, in her best Amy impersonation.

Fortunately, when the scene wrapped, Parsons could rest and Bialik did not get the flu.

19 Melissa Rauch Had To Be Pushed To Be Meaner

Rauch was nothing like her feisty character, Bernadette and had to be encouraged to become more assertive

Melissa Rauch wearing a shiny black dress
Via: Instar

Melissa Rauch's character, Bernadette, was very feisty on Big Bang Theory. In real life, Rauch is more laid back. Because of this, Rauch had to be pushed to be more assertive, according to USA Today, in order to make a scene look realistic versus like a performance.

"At the very end, when we all run back into the apartment to look under Sheldon’s spot, Melissa is supposed to push me out of the way, and I was like, ‘Push me! Push me!’" Kaley Cuoco explained. " And she just shoved me in one of the takes and I ran into the pole in the living room set. And we’re both trying not to laugh. (But) we’re facing away from the camera and I’m literally crying, I’m laughing so hard. And she’s crying, too. We were laughing so hard.”

Johnny Galecki said he experienced the same issue with Rauch in the same episode.

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"She had to punch me. It looked so lame and fragile," Galecki explained. "And I kept saying, 'Hit me!'"

"She couldn’t do it," Cuoco said. "It was very cute."

18 Kaley Cuoco Got Tired Of Having To Deny Her Feelings For Johnny Galecki

Kaley Cuoco and Johnny Galecki dated for two years before breaking up

Kaley Cuoco on the red carpet
via Instar

Cuoco and Galecki were a real couple for over two years. But it was not until after the romance ended that the public found out about it.

After the relationship was revealed, Cuoco discussed how the two were able to keep things secret and ultimately, why Cuoco and Galecki called things off.

"We dated for almost two years. It was such a huge part of my life and no one knew about it," Cuoco revealed at the time. "This is the first time I've ever talked about it, ever. It was a wonderful relationship, but we never spoke a word about it and never went anywhere together."

Cuoco went on to say, "We couldn't do anything. It wasn't as fun as we wanted it to be. Everyone was always asking, and we deny-deny-denied. And I'm like, 'Why am I denying this person that I love?'"

Despite breaking up, Galecki and Cuoco were able to keep things professional on the set.

"We knew we weren't destined to be together. We accepted it and said, 'Look, if we ever break up, we will be professional,'" Cuoco said. "I'm so lucky it was a mutual ending and that we don't hate each other. We've seen that happen on other shows."

17 Kevin Sussman And John Ross Bowie Teamed Up For Side Projects

Kevin Sussman and John Ross Bowie had two projects purchased but were never greenlit

Kevin Sussman on the red carpet
via Instar

In 2011, Kevin Sussman (Stuart Bloom) and John Ross Bowie (Barry Kripke) teamed up to write a couple of scripts to see if they could be purchased and developed. While things looked to be initially fruitful, eventually, the scripts they wrote were never picked up.

Bowie and Sussman first got on the studios' radars for writing Dark Minions. The project was picked up by Sony, but it was never developed.

The next project that Sussman and Bowie worked on together was a script called The Ever After Part. Fox purchased the script, but unfortunately, it was never developed.

After neither project worked out, it looked like both projects were dead in the water. But in 2017, it looked like Fox was going to redevelop The Ever After Part. However, the project again fizzled and has not been touched since.

16 Jim Parsons Had No Idea Who Chuck Lorre Was When He Got The Chance To Audition

Jim Parsons thought Chuck Lorre was Chuck Woolery

Jim Parsons on the red carpet
via Instar

Chuck Lorre is a very popular name in the world of television. However, before auditioning for Big Bang Theory, Parsons did not know who Lorre was. In fact, he thought Lorre was someone else entirely.

"I didn't know anyone involved (in the show), in fact when I got the call, my agent said, it's the new Chuck Lorre pilot... he was clearly excited," Jim Parsons explained. "I did not know Chuck Lorre at the time... but I thought he was talking about Chuck Woorlery!"

Parsons nailed the audition, got the role, and needless to say, is very familiar with Lorre these days.

15 Kevin Sussman Has A Fear That Made Filming One Scene Very Hard For Him

Kevin Sussman has a fear of going under water

Kevin Sussman on the red carpet
via Instar

A lot of people think it’s fun to be underwater, Sussman is not one of them. In fact, he has a fear of going underwater. As such, when he had a scene with Kunal Nayyar that involved a hot tub, Sussman was not sure how he was going to get through it.

"I don’t like putting my head underwater ever..." Sussman explained. "A bunch of people had to coach me, you know, ‘it’s going to be okay, we have a lot of people around.'"

Eventually, Sussman got through it but it was not one of his better days on set.

14 The Original Big Bang Theory Pilot Didn’t Have A Character Named Penny

The original female lead in Big Bang Theory was Katie

Leonard, Penny and Sheldon on The Big Bang Theory
via CBS

Penny almost was not a part of this show at all. Instead, the original pilot (which never aired on television), according to Ranker, featured a very different woman named Katie. A character who was seen as "too mean" to Leonard and Sheldon.

Because the character, played by Amanda Walsh, did not test well with audiences, the script had to be rewritten. This is when the writers came up with the character of Penny.

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Walsh was not seen as a good fit for the role. This opened the door for Cuoco to audition for the role, which she was perfect for. And the rest, as they say, was history.

13 Jim Parsons Has Never Seen Some Of The Shows Sheldon Loves

Jim Parsons out in NYC
via Instar

Sheldon may be a Trekkie, but Parsons couldn’t be more different. This is because Parsons has never seen an episode of Star Trek and has never had any interest in doing so.

Instead, Parsons was a big fan of Grey's Anatomy and enjoyed hosting Saturday Night Live. Neither of which Sheldon would ever want any part of.

12 Soft Kitty Is Not Totally Original

Soft Kitty is a song that was adapted from Warm Kitty, a song written in 1937

Penny singing Soft Kitty to Sheldon, Big Bang Theory
via YouTube/CBS

The ever-popular song in The Big Bang Theory, "Soft Kitty", was first introduced to the show during the episode, The Pancake Batter Anomaly. It was used several other times throughout the show as a song that calms down Sheldon and others when ill or feeling blue.

A very similar song, "Warm Kitty", was published in 1937. The songs are nearly identical, which caused a lawsuit to be filed by the composer's daughters. However, NBC and the creators of BBT went through all of the proper channels to purchase the rights to the song to ensure those who needed to be compensated were.

The lawsuit was eventually dropped, and "Soft Kitty" remained on the show.

11 Halley Was A Tribute To The Actress Who Played Mrs. Wolowitz

Halley was never seen on camera because Mrs. Wolowitz was not either

Leonard and Bernadette in bed listening to Halley, Big Bang Theory
via YouTube/CBS

Howard and Bernadette’s child, Halley, who was born in 2016, was never seen on camera. While viewers may have thought this was so that a baby did not have to be on the set (which was partially true), the real reason Halley was never seen was much more heartwarming instead.

"She is a loving tribute to her grandmother — this is a nice way for us to keep [Mrs. Wolowitz] alive," showrunner Steve Molaro explained. "It also means we don't have to have a baby on the set, so it solved lots of problems."

Carol Ann Susi, who played Mrs. Wolowitz, passed away in 2014.

10 Actors Had To Work While They Were Injured

Kaley Cuoco's leg was almost amputated, and Mayim Bialik was in a car accident

Kaley Cuoco as Penny working as a bartender from The Big Bang Theory
Via: CBS

A few of the actors on the show worked while they were injured. Instead of shutting down production, however, the creators of the show worked around the injuries.

Cuoco went out for a riding lesson in 2010, and got thrown from the horse. The injury was so bad that doctors thought they were going to have to amputate her leg. Fortunately, they were able to set the leg with the broken bones, and the limb was saved.

However, this meant that Cuoco had to work with metal rods in her leg. To work around it, Cuoco became a bartender and no one in the audience was any wiser that the storyline was originally what the writers intended to do.

A few years after Cuoco's accident, Bialik was involved in a car accident. While she was okay, she injured her right hand pretty badly. While it did not require surgery, Bialik was limited in what she could do. But she assured fans that the show was "going to make it work."

"As long as I'm not dancing or walking," Bialik explained, "we're good. No handstands."

9 There Was A Reference To Mayim Bialik Before She’d Even Been On The Show

Mayim Bialik was referenced from her hit show, Blossom

Mayim Bialik, Los Angeles LGBT Centre Gala
Instar

There is a reference to Bialik way back in season one, even though she didn’t become a part of the cast until much later.

According to imdb.com, this episode is called “The Bat Jar Conjecture,” and in it, Raj mentions the girl who starred in Blossom, which is Mayim.

8 Kaley Cuoco Had A Very Short First Marriage While On Big Bang Theory

Kaley Cuoco and Ryan Sweeting were married for two years

Kaley Cuoco and Ryan Sweeting
Instar

Cuoco has never been one to shy away from a relationship. Because of this, she got engaged to tennis player Ryan Sweeting just three months after they met. It looked like the two were going to be very happy together.

However, two years after Cuoco and Sweeting married, Cuoco filed for divorce. The reason the two split was because of Sweeting's substance abuse.

"Kaley gave him an ultimatum," a source explained. "'If you don't stay sober, then I'm done.'"

While Sweeting went to rehab, when he got out he disappeared. It was then that the marriage was over.

7 Kaley Cuoco Didn't Live With Her Second Husband

Kaley Cuoco and Karl Cook were married for three years

Karl Cook and Kaley Cuoco
via Instar

Kaley and her second husband, equestrian Karl Cook, did not reside under the same roof for two years after they got married. While it was explained away as the couple's "dream house" was being built and that when it was done they would live together, living apart appeared to make it so the couple could not grow together.

It was not until 2020 that the two moved in together. And it was in 2021 that Cuoco and Cook realized they were better off not living with one another and not being married. As such, the two filed for divorce.

6 Howard And Raj Were Not A Part Of The Original Pilot

Howard and Raj were originally played by one character, Gilda

Simon Helberg and Kunal Nayyar both enjoy their restaurant perks as celebrities
via: Instar

The original pilot for this series was nothing like the show audiences love today. In addition to Katie being the female lead character, Raj and Howard were not part of the original cast. Instead, it was a character named Gilda.

Gilda's character was supposed to like Leonard and have issues with Sheldon. However, the audience was lukewarm to the character. And with the rewrite that was already happening to bring in Penny, Gilda was scrapped. Instead, Raj and Howard replaced Gilda.

The idea of Gilda was not completely put aside, however. The character eventually became the inspiration behind Leslie Winkle.

5 There Were Some Hiccups In Simon Helberg's Real-Life Relationship

Simon Helberg went to great lengths to win his wife back

Simon Helberg at Cannes
via Instar

Simon Helberg's character, Howard, may fancy himself a ladies' man, but Helberg admitted he was not. In fact, he disrupted his relationship so badly with his then-girlfriend, Jocelyn Towne, that the two almost broke up. But with a huge romantic gesture, Helberg won her back.

"Our relationship, the breakup, the following to Paris, her meeting a violin-playing Frenchman and staying in his apartment, the groveling, proposing in the car, completely sabotaging that…all of that stuff is unfortunately pretty much ripped from our headlines, but kind of the flourishes and other characters are fictionalized," Helberg explained about a movie he and Towne wrote that was based on their relationship. "Believe it or not, and I don’t know if it’s a point of pride, but it’s probably the clumsiest attempt at declaring your love for someone that’s ever been lived or depicted."

4 Some Of The Marital Issues In The Show Were Inspired By Real Life

Writers used their own marital issues for storylines in the show

Penny forgets Leonard's birthday, Big Bang Theory
via YouTube/CBS

Some of the comedy in the show centers around marital troubles. Much of the comedy was inspired by some real-life events of the writers, who had no problem with putting their issues on the small screen to be worked out by the characters.

One of those times was when Penny forgot Leonard's birthday. This was something that really occurred with one of the writers on the show. And while it may not have been funny in real life, on The Big Bang Theory, it was incredibly comical.

3 Wil Wheaton Left A Different Hit Show And Regretted It

Wil Wheaton wished he never left Star Trek: Next Generation early

Wil Wheaton at 'Stranger Things' 35th PaleyFest Los Angeles
Via: Instar

Before Wil Wheaton was on this series, he was on Star Trek: The Next Generation. Thinking he was making a "smart business career move," Wheaton left the series to pursue other ventures. While he would come back to guest star on the show, he realized too late that leaving was ultimately the wrong decision.

"I was 18 years old and initially I thought it was a really smart business career move," Wheaton explained. "In some ways it was and in more ways it wasn't. What I wasn't prepared for was how much I was going to miss the people that are on this stage."

Wheaton went on to say, "After that ended, I just felt really ashamed of myself. ... I felt like I couldn't look them in the eye — I felt like I didn't have the right to invite them to my wedding."

2 The Writer’s Strike Had A Big Impact On The Show

The writer's strike in 2007-2008 caused the first eight episodes to be played on repeat on CBS

Big Bang Theory cast
via CBS

During the first season of Big Bang Theory, there was a writer's strike going on. Only eight episodes had been written when the 100-day strike occurred. As such, NBC was forced to air the episodes multiple times during the strike having no one to write new material.

Despite this, the ratings for Big Bang Theory held strong. As such, NBC knew they had a hit on their hands and were ready for writers to get back to work when the strike ended in 2008.

1 Some Of The Characters Looked Very Different In The Original Pilot That Never Aired

Leonard and Sheldon wore dressier, out-of-date fashion that transformed after the pilot was re-written

Johnny Galecki, Jimmy Parsons and Kaley Cuoco on The Big Bang Theory
via CBS

The costumes in The Big Bang Theory usually make the characters seem much more relatable since they all dress in a pretty average way unless they’re at work. But, according to imdb.com, Leonard and Sheldon dressed in more formal clothing that was not relatable to audiences. As such, when the pilot was re-written, a fresher approach was used for the wardrobe, with each character having their own unique fashion sense.

Source: Mental Floss, USA Today, CBS Local, Ranker, TVOM, Deadline, Geeks, IMDb