A running gag is a joke that pops up throughout the series or in more than one episode. Since The Big Bang Theory ran for 12 seasons, there were over 270 episodes filled with memorable moments and, more importantly, running gags.
With the help of Sheldon, Leonard, Raj, Howard, and their significant others Penny, Bernadette, and Amy, The Big Bang Theory became one of the most beloved series' on TV. With a storyline revolving around Sheldon's genius and how his best friends and (now) wife learn to navigate life with him, we've seen hilarious moments mixed with their love of science. But with the series ending back in 2019, we're left missing some of our favorite gags from the series.
SHELDON NEVER UNDERSTANDING SARCASM
Sheldon may be a grown man but his understanding of basic common-sense is lacking. When it comes to the human connection and basic emotions, Sheldon is at a loss. The act of sarcasm (above all) is something that took him years to grasp (and even then he still didn't always understand when it was happening).
Penny and Leonard are two of the most sarcastic people on the series and, since they're both practically Sheldon's best friends, he had a hard time knowing when they were serious and when they were joking. We felt bad for Sheldon's lack of social awareness at times but not when it came to sarcasm.
PENNY'S 'CHECK ENGINE' LIGHT
"Your 'check engine' light is on" is something we heard throughout The Big Bang Theory. Before Penny made it big as a pharmaceutical sales rep, she was a struggling actress for years. She worked as a waitress at the Cheesecake Factory to pay rent and her only means of transportation was a beat-down car.
The car's 'check engine' light seemed to always be on but it never worried Penny because it had been on for months. For nervous travelers like Sheldon, Amy, and Leonard's mom, however, the thought of her car breaking down mid commute was a nightmare. Eventually, Penny's car did break down but it is difficult not to think of this running gag when we see our own 'check engine' lights on.
HOWARD NOT HAVING HIS PH.D
Howard is an exceptional engineer who has been in control of the Mars Rover and has even been to space. He's extremely accomplished in his field and yet his friends can't seem to drop the fact that he doesn't have his Ph.D.
Everyone in the group (except for Penny) has their doctorate and is seen as the highest achievement in their fields, however, Howard's resume eludes one. He did try to get his doctorate, of course, but having Sheldon as his professor wasn't doing anyone a favor.
THE ROOMMATE AGREEMENT
Ah, the Roommate Agreement. Thanks to one of Sheldon's many quirks, he believed having an agreement between roommates would make their living space more comfortable. The Roommate Agreement included things like a bathroom schedule, a rule on having company over, the perfect temperature for the apartment, and even roommate meetings.
Leonard was a good sport for a while but there were times when he just wanted to live freely and not have to adhere to an agreement. Funny enough, when Leonard and finally got to live with Penny, he forgot how to live a life without rules (i.e. where to eat on a Thursday night).
RAJ'S MUTISM
When first introduced, Raj couldn't talk to girls. He had selective mutism, where his nerves were so high-strung that talking to a girl seemed impossible. The only way he was able to speak to Penny was through Howard and Leonard.
Over time, Raj realized he could speak to any woman with a little liquid courage but he didn't want to rely on alcohol forever. That's when in the sixth season, Raj met a woman named Lucy (who was as nervous as he was) and decided to fight his selective mutism once and for all. Raj did relapse in the 12th season but Anu was understanding of it.
AMY'S GIRL CRUSH ON PENNY
Amy's character grew considerably throughout the series. She was once robotic before becoming obsessed with Penny and wanting to be her friend. It got to the point where Penny actually enjoyed hanging out with her and the two had regular girls nights with Bernadette.
That said, was Amy's friendship with Penny really just a crush? In "The Agreement Dissection," Amy kisses Penny at the bar and ends up singing "I Kissed A Girl" in the car ride home. She is also seen brushing her hair and wanting to be apart of her "world." Nevertheless, whether she was infatuated with Penny or just wanted to be friends, this running gag never got old.
AND HOWARD & RAJ'S CLOSE BOND
Before Howard found love with Bernadette, many fans were hoping that Howard and Raj would end up together. They were two best friends who were incredibly close and did everything together.
Raj was the more emotional of the two and his comments towards Howard could be seen as romantic. Sadly, these two stuck to being friends and never had that romance so many fans wanted.
STUART'S LONELINESS
Loneliness and depression aren't funny topics but leave it to Stuart to make them comical. Thanks to Stuart owning the comic book store the guys went to, he became a special part of the group (when he was actually invited to things). However, whenever Stuart wasn't invited to the gang's weekly shindigs, he made sure to bring his absence up (but it never made too much of a difference).
Stuart frequently made fun of everything from his homelessness, pale complexion, lack of confidence, and bad luck in the relationship department. Thankfully, Stuart ended up changing his life around by the last two seasons.
BERNADETTE SOUNDING JUST LIKE HOWARD'S MOM
When we first met Bernadette in the third season, she was this sweet little woman with a high-pitched voice. She thought everything Howard said was hilarious and loved his tight pants. Over time, however, Bernadette's personality shifted.
Sure, Bernadette still adored her husband but her tone with Howard began to transform into his mother's. Whenever she was upset, Bernadette's voice would escalate and sound identical to Howard's mother, which was disturbing because the latter mentioned how hot she sounded...
THE NUMBER OF TIMES PENNY & LEONARD BROKE UP
How many times do Leonard and Penny break up? It's hard to count by the 12th season! Even though Leonard and Penny finally got married in season eight, these two played cat and mouse with each other for years before they got to a stable point in their relationship.
While fans only saw Leonard and Penny break up once or twice, there's a running gag that these two have broken up multiple times (and have even proposed to each other multiple times). Howard even has names for their breakups! Thankfully, by season 12, these two have a stable marriage and can laugh about their fluctuating past, but it was still one of the sitcom's best running gags.