
In the 17th episode of the debut season of “The Big Bang Theory,” something huge happens: Leonard Hofstadter (Johnny Galecki), the nerdy roommate and best friend of Sheldon Cooper (Jim Parsons), is brave enough to ask out their neighbor Penny (Kaley Cuoco), arguably the girl of Leonard’s dreams. According to Jessica Radloff’s 2022 book “The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series,” this moment was a long time coming, even though it was relatively early in the show … and audiences responded very, very well.
After the show took a hiatus following just a handful of episode due to the 2007-08 writers’ strike (but returned as an even bigger sensation than before), creator Chuck Lorre said that the audience showed their love for the series in a big way while they filmed the aforementioned episode, titled “The Tangerine Factor.” As Lorre recalled:
“It was one of those moments that led me to believe something special was happening, beyond what we’d ever imagined. People were even coming to the taping dressed in lab coats and things! The audience was totally invested in these two fictional characters. And the fact that there was hope for that relationship is why they were applauding, cheering. You know, ‘Oh boy, Leonard’s gonna have the dream date!’ And when the audience cares about fictional characters, it’s wonderful. I know it’s make-believe, but you still get swept away.”
For his part, Galecki agreed and stated, “I remember it because in the first failed pilot the audience was not rooting for Leonard and Katie, so it felt great to have that enthusiasm for Leonard and Penny. That’s exactly what I had hoped for when joining the show, to be in these stories involving matters of the heart. The audience went crazy.” After saying that the audience also loved a moment, seasons later, when Penny tells Leonard she loves him (a moment that made both Cuoco and Galecki cry in real life), Galecki continued, “I get very emotional thinking about it now. You can’t create that out of nothing. Those sentiments came from honesty and reality.”
Leonard almost didn’t ask Penny out in the original draft of this Big Bang Theory episode

The basic plot of “The Tangerine Factor” is as follows: After breaking up with yet another crappy guy, Penny is feeling down when Leonard asks her out on a date — but she’s conflicted because Leonard is a good friend, and she doesn’t want to ruin the relationship they already have. Incredibly, both of them end up asking Sheldon for advice, but the wisdom he imparts to Penny is unexpectedly helpful. Sheldon uses a scientific principle known as Schrödinger’s Cat, saying, “Just like Schrödinger’s Cat, your potential relationship with Leonard right now can be thought of as both good and bad. It is only by opening the box that you’ll find out which it is.”
However, according to “The Big Bang Theory” co-creator Bill Prady (who penned the episode alongside executive producer and writer Steve Molaro), Leonard and Penny’s shared leap of faith nearly didn’t happen. “Steve and I wrote that episode, and we were struggling because in the original outline he never asked her out at the end,” Prady told Jessica Radloff. “The original version of the story was Leonard imagined going out with Penny, and he decides to rehearse the date with Sheldon playing the part of Penny. And the rehearsal goes so bad that he doesn’t ask her out. We worked on it for hours and hours, until we finally called Chuck. He said, ‘This doesn’t make sense; no matter how bad the rehearsal date goes, it’s Sheldon’s fault. It’s not actually Penny there, it’s Sheldon. See what happens if he asks her out.'”
“So, we went back, and I think we got to the place where if we asked her out, we couldn’t think of any reason why she wouldn’t say yes,” Prady concluded, before saying that he understands the baseline attraction between the two:
“I think she would be curious. And even though Leonard found her very attractive, that wasn’t the basis for his interest in her. He was a different kind of guy for her. All men start by being attracted to someone, and for some men, that’s enough. But Leonard isn’t that kind of person. He was a different kind of man for Penny than those she had previously encountered. It was the first of many, many times when we’d write ourselves into a corner at the end of the year and hope that we or the other writers who showed up after a hiatus could figure out a way out of it.”
Fans of the series know that Leonard and Penny are one of the show’s central couples, so clearly, this worked out … but it’s borderline stressful to imagine a world where Leonard never plucks up the courage to ask Penny out on a date.
One particular fan’s feedback helped a Big Bang Theory director realize the show was universal
Ultimately, after “The Tangerine Factor” aired, the people who worked on it, including director Mark Cendrowski, got some unexpected feedback — in a good way. As Cendrowski told Jessica Radloff, his daughter played softball at the time and one of her coaches, whom Cendrowski said also worked in construction, approached him to ask if he directed episodes of “The Big Bang Theory.”
“I was shocked he even knew that, but also because he just didn’t seem like the type of guy I expected to watch it,” Cendrowski continued. “But he said, ‘What Leonard is going through … you don’t have to be a nerd to understand what it’s like to have trouble talking to a beautiful girl.’ And that’s when I realized, Oh, these stories are universal. This is not just for a specific audience. I went home saying, ‘I feel very good about this show.'”
Cendrowski’s instincts were right; Anyone reading this has probably taken some sort of romantic leap, and it’s hard, as we see while both Leonard and Penny grapple with the idea of dating each other. After an on-again, off-again romance, the two end up getting married and, in the series finale, even find out that Penny is expecting a baby (a development that shocked Johnny Galecki). If you want to watch all of Leonard and Penny’s love story starting with “The Tangerine Factor,” you can stream “The Big Bang Theory” on HBO Max now.