After 12 seasons, The Big Bang Theory came to a close on Thursday night

By Jodi Guglielmi
May 17, 2019 10:57 AM

Now that The Big Bang Theory is over, Kaley Cuoco is spilling all the secrets.

Cuoco appeared alongside her Big Bang Theory costars on The Late Show with Stephen Colbert on Thursday following the series finale of the hit comedy. After dishing on what they’d taken from set and which other character they’d like to play, Cuoco was asked the question fans have been pondering for the last 12 years: What is Penny’s last name?

“You’ll never know,” she joked, before confessing, “There really is no answer.”

Cuoco reveled that Penny was never given a last name and after a few seasons, the decision was made to keep it that way.

“She’s Cher — one name!” Cuoco said. “It became a little superstitious for me, too.”

Sonja Flemming/CBS via Getty

Jim Parsons, who starred as Sheldon on the series, said he never realized she wasn’t given a last name.

“We don’t even call your parents Mr. and Mrs. anything,” he said. “I never noticed this!”

After 12 seasons, The Big Bang Theory came to a close on Thursday night, with back-to-back episodes that wrapped up several long-running storylines for the beloved geeks.

The CBS sitcom — which, at 279 episodes, is the longest-running multi-camera series in TV history — aired a funny yet emotional goodbye.

Series regulars Leonard Holfstadter (Johnny Galecki), Sheldon Cooper (Parsons), Penny (Cuoco), Howard Wolowitz (Simon Helberg), Amy Farrah Fowler (Mayim Bialik), Bernadette Rostenkowski-Wolowitz (Melissa Rauch), Rajesh “Raj” Koothrappali (Kunal Nayyar), and Stuart Bloom (Kevin Sussman) were all there, each getting their own versions of their happily ever afters.

The night started with an episode titled “The Change Constant,” before moving to the final episode, “The Stockholm Syndrome.”

Michael Yarish/CBS

Filming for the episode happened on April 30. The last scene of the whole series was pre-taped, and hidden not just from the studio audience, but also from the entire cast.

“It seemed like a nice thing for us to hold back one piece of the finale, so there’s at least one thing that couldn’t be spoiled,” showrunner Steve Holland previously said. “That way it will also make the night extra special for those who were at the taping because there’s an extra piece.”

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Speaking to PeopleTV on the Paleyfest red carpet last March, the cast admitted they couldn’t really picture their life after the series finale.

“I actually can’t, to be honest,” said Cuoco, 33. “I can’t really picture it. And I don’t think there really will be my life without it — I think it’ll always be there, I think it’ll always be running, I think we’ll always have those fans. It’s always going to be a part of me.”

Nayyar, 38, said the ending would be “very sad.”

“I grew up on this show — I was a kid out of grad school,” he said. “I don’t even know how to comprehend that.”

The Late Show airs weeknights at 11:35 p.m. ET.