Warning: Spoilers for the series finale of The Big Bang Theory ahead.
The 33-year-old star told TVLine that she was as shocked as anyone when she learned that Penny would be the first Big Bang character to ride the apartment building's long-broken, finally-repaired elevator.
"The fact that I got that moment... I will cherish that for the rest of my life," she said, adding that the studio audience at the taping "screamed for like five minutes" when the elevator doors opened and Penny was revealed to be inside.
Showrunner Steve Holland told the outlet that he gave Penny the "big moment" because "it just felt right for the story."
Although the elevator ride was originally intended to arrive "later in the [second] episode" of the two-episode finale event, Holland said, "As we were breaking the story, it just felt like this was a great time to do it. And I think it was more of a surprise coming so early in the penultimate episode rather than the last episode."
Cuoco was so surprised that Penny got to ride in the elevator that it even "surprised me more than Penny being pregnant!"
Penny and Leonard's pregnancy reveal served as the main plot point throughout the entire final episode, with Penny and Leonard unable to hide their secret as they flew with the rest of the characters to see Sheldon and Amy receive their Nobel Prize.
Despite the happy news, Sheldon reacted in his own selfish way, pushing a wedge in between the friend group for the bulk of the episode until he gave a loving speech on the stage while receiving his award.
And although fans never got to learn Penny's last name, she's got a new last name at this point and a future full of motherly love. Cuoco told TVLine last week that she wasn't bothered by never learning her character's surname.
"I kinda love it," she said. "'Cause so many things are revealed in the last few episodes, you get a lot of satisfying moments, I'll tell you that. But that I kind of love."
"I love it too, 'cause Johnny [Galecki] always says, 'It's Hofstadter! It's Hofstadter, that's her last name,'" she said, referring to his character Leonard's last name.
Cuoco took to Instagram to share an intimate moment behind the scenes of the finale during the cast members' "final curtain call" in which they stood arm in arm in a big huddle.
View this post on Instagram
"Our final show. Our final huddle. Our final curtain call," Cuoco captioned the clip, adding, "it doesn't get more [behind the scenes] than this."