For fans of "The Big Bang Theory," Penny was a bubbly, personable foil to her nerdy neighbors, not to mention an accessible point of entry for those non-physicists among us. Indeed, told in 2019 that her character served as "the eyes and ears for the actual audience." The actress added, "It helped people understand and it helped people laugh whenever she'd give a funny look [to the guys]." Cuoco joined the immensely popular series upon its inception in 2007 and played Penny for a total of 279 episodes, winning a Satellite Award, a Critics Choice Television Award, and back-to-back People's Choice Awards (via ).

Penny is an aspiring actress living across the hall from physicists Leonard Hofstadter (Johnny Galecki) and Sheldon Cooper (Jim Parsons) in their Pasadena apartment. Initially introduced as the guys' extroverted neighbor, the character quickly became a staple of the series' dynamic, developing affection for Sheldon, love for future husband Leonard, and and Bernadette (Melissa Rauch). It was events that unfolded off-screen, however, that would ultimately shape Penny's on-screen arc.

A real-life accident paused Penny's waitressing career

At the outset of "The Big Bang Theory," Penny is working as a waitress at The Cheesecake Factory while pursuing her ill-fated acting career on the side. While the greatest hits of her acting work include a hemorrhoids ad and a B-horror film called "Serial Apeist," she does eventually get a new gig at The Cheesecake Factory — but not for the reasons you might think.

In a 2010 interview on Cuoco revealed why her character was suddenly switched from waitress to bartender in Season 4. Rather than an endorsement of Penny's bartending abilities, Cuoco admits it was due to a real-life horse riding accident. After being bucked off of her spooked horse, the animal accidentally trampled the actress. Cuoco describes the scene in gory detail: "I heard [the crackling] and I thought he landed on leaves, and I was hoping it was leaves I was hearing crackling, but that was my bones ... I'm not feeling anything, and then I looked. And I'm like, 'Wow, my foot is facing me ... That's not normal.'"

After missing a couple episodes of Season 4, Cuoco returned in "The Apology Insufficiency" wearing a full leg cast (via ). To hide her injury, the show's writers decided to stick the actress behind the bar. Though it may not have been the career bump Penny wanted, her new status as bartender gave her the opportunity to establish some new comedic bits, like tricking Sheldon into drinking a Long Island Iced Tea, as well as adopt the tried and true bartender-as-therapist persona. Since 2010, Cuoco seems to have avoided any more horse-related injuries, and that's probably for the best. In her new, highly kinetic series it would be decidedly more difficult to hide such a hefty injury, especially if she's serving drinks on a plane.