The Big Bang Theory Storylines That Went Absolutely Nowhere

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“The Big Bang Theory” ended in 2019 after 12 seasons. For much of this time, it was one of the most popular sitcoms on TV and juggled a whole bunch of storylines to keep things interesting. Several characters went through numerous changes and ended the show in considerably different places than where they started — which, of course, is only natural. That’s how life should work, even for fictional characters.

The flip side of the show’s lengthy existence and numerous arcs is that every once in a while, something slipped through the cracks. It wasn’t just a single something, either. In fact, there were several storylines that “The Big Bang Theory” treated as significant at one point in its run, only to completely bury them a little later while pretending that nothing much had happened. 

Of course, such side quests are also a part of life, and not everything is meant to last. Still, for an observant viewer, the show is surprisingly full of storylines that abruptly hit an absolute brick wall. Here’s a look at five of the biggest “The Big Bang Theory” storylines that went absolutely nowhere.  

Cinnamon the Yorkshire terrier used to be such a big deal. The Season 5 newcomer entered the “Big Bang Theory” fray as Raj Koothrappali’s (Kunal Nayyar) beloved new pet, which he received as a gift from Bernadette Rostenkowski (Melissa Rauch) and Howard Wolowitz (Simon Helberg) when she was but a pup. Raj almost immediately developed a somewhat worrying affection for the dog, pampering her for a good couple of seasons. In fact, for a while, it seemed that the adorable Yorkie was set to become the show’s contribution to the best TV animals of all time, joining sitcom all-timers like Marcel the Monkey from “Friends” or Eddie from “Frasier.” 

Alas, this wasn’t meant to be. Despite getting her share of limelight, Cinnamon slowly faded into the background. Before long, she was reduced to extremely rare and brief cameos and references that left her with less agency than the average couch pillow on the show. It got to the point that her crowning late-game glory was peeing on Leonard Hofstadter (Johnny Galecki) off-screen in the Season 10 episode “The Collaboration Fluctuation.” 

Sure, it’s possible that the show realized that there was only so far it could take the extent of Raj’s affection with the little dog (which, uncomfortably, was framed like a girlfriend expy of sorts early on). As such, “The Big Bang Theory” may have simply decided to carefully step away from the animal and explore other avenues of comedy. 

One of the great could-have-beens of “The Big Bang Theory” was Sara Gilbert’s straight-shooting Leslie Winkle, who brought chaos to the university (and a couple of main characters’ romantic lives) during the show’s early period. However, after Leslie memorably established herself as a recurring character in Season 1 and as part of “The Big Bang Theory” main cast in Season 2, she abruptly left the show in Season 3 and wasn’t seen again until a brief and largely inconsequential guest appearance in Season 9.

Leslie was a fun foil for the comparatively meek main characters — Leonard in particular — and brought plenty of laughs with her invariably hostile attitude toward Sheldon Cooper (Jim Parsons). However, Jessica Radloff’s 2022 book “The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series” shed some light on the reason behind Leslie’s comparatively quick exit, courtesy of executive producer and writer Steve Holland, who framed the character as a thematic experiment that simply didn’t work out. 

“There was always a desire to have more female scientist representation because it was a very male-heavy show,” Holland said. “It wasn’t a thing where we were like, ‘We’re going to write this character and have her be part of the show,’ but it was a thought that this was important for us to do. Bill [Prady] and Chuck [Lorre] wanted to highlight women in science as well, but it had to be the right role. You don’t just write a new character and say, ‘This is our new female scientist.’ You have to find the right roles for people. Sara Gilbert kind of filled that role early on, but she wasn’t part of the show as much by Season 3.”

Remember the absolutely gigantic, sled-like time machine from George Pal’s 1960 H.G. Wells movie “The Time Machine,” which Leonard ends up buying in Season 1 of “The Big Bang Theory”? The one that the characters become completely (and honestly, understandably) obsessed with for a while? The machine first appears in Season 1, Episode 14 (“The Nerdvana Annihilation”) and is pretty heavily set up as a fun running joke. Sheldon, Leonard, Raj, and Howard are all super excited about the acquisition, and even when Penny hobby-shames Leonard into abandoning it, the machine seems destined to become a recurring fixture. Instead, the show dropped the whole prop like a hot potato, never to be seen or even discussed again.

It’s worth noting, however, that there’s a decent chance that “The Big Bang Theory” franchise intends to fix the time machine’s lengthy absence before long. The upcoming “The Big Bang Theory” spin-off “Stuart Fails to Save the Universe” focuses on Stuart Bloom (Kevin Sussman) breaking reality after messing with a very particular machine, requiring him to (fail to) save the universe in order to fix the damage. It’s still unclear precisely which machine is the show’s central MacGuffin and how Sheldon and Leonard have managed to build it, but it wouldn’t be all that surprising if the device looked a whole lot like a certain impulse purchase one Mr. Leonard Hofstadter made all those years ago.

Doctoral student Alex Jensen (Margo Harshman), who became Sheldon Cooper’s not-so-long-suffering assistant, seemed like a major addition for “The Big Bang Theory” in Season 6. She was a comparatively prominent female character who was also one of the precious few normal folks on the show, providing a great dynamic with resident and self-admitted weirdo Sheldon and, frankly, everyone else. What’s more, she came with a hefty side order of drama. Slowly and steadily, she joined the ranks of female “The Big Bang Theory” characters who inexplicably become interested in Leonard Hofstadter. This obviously put her on a collision course with Penny. But what direction would Alex’s character take from that point on?

Good questions. Unfortunately, the answer to all of them was that things wouldn’t continue at all. Instead, Alex became a very minor background presence. After just four episodes, she was faded out — possibly because Harshman was playing major recurring character Delilah Fielding-McGee on “NCIS,” or possibly because Alex simply became another female character “The Big Bang Theory” couldn’t figure out how to handle after her powerful initial arc. 

At one point early on, the makers of “The Big Bang Theory” realized the disparity of featuring multiple male genius main characters and a sole female one who was a waiter-slash-bartender, and who didn’t even get a last name until she married Leonard. Because of this, the show started hurriedly introducing female scientist characters like Leslie Winkle, Bernadette Rostenkowski, and Amy Farrah Fowler (Mayim Bialik). However, possibly out of a need to keep an “average Jane” character to ground all these unhinged scientist types, “The Big Bang Theory” routinely undermined every attempt Penny (Kaley Cuoco) made to improve herself and pretended that they never happened in the first place. 

A possibly incomplete but nevertheless worryingly long list of Penny’s self-betterment cut short includes her multiple potentially profitable business ideas, such as the shoe-shopping app she’s brainstorming with Sheldon in Season 4’s “The Bus Pants Utilization” and her genuinely clever and successful Penny Blossoms hair decor business in Season 2’s “The Work Song Nanocluster.” Despite their potential to elevate Penny on the field of business — they were soon largely forgotten, resetting Penny’s status back to a comparative educational and financial pariah.  

Perhaps the most egregious example of the show’s “never give Penny a major intellectual win” credo is her time at Pasadena Community College, which was a big thing in Season 6 episodes before the show quietly buried it. What’s more, much of the attention was devoted to her attempts to study without interference — for example, Leonard’s attempts to secretly read her history reports and generally meddle in her affairs.