Kaley Cuoco and Johnny Galecki reflect on "bittersweet" end of "Big Bang Theory"

Cuoco & Galecki on "Big Bang Theory" finale

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Thursday night marks the end of an era for TV comedy. After 279 episodes, "The Big Bang Theory" is coming to an end. The hit CBS show is now the longest running multi-camera comedy in TV history. It has provided nearly 12 years of laughs, with some of television's most endearing and unique characters.

"It's very bittersweet," Johnny Galecki, who plays Leonard Hofstadter on the series, said Thursday on "CBS This Morning." "The quote from Winnie the Pooh keeps coming up in my mind, the 'how lucky I am to be this sad to say goodbye' to something. You know, we all feel very, very grateful, but the timing is right."

"Yeah, it is kind of like a death in a way. You know?" star Kaley Cuoco, who plays Penny. "I mean, it's been a long, long time together."

Cuoco described the final episode as "beautiful."  

"There's a lot of anxiety for months on how this is going to end, for the writers and for us too. And I'm really trying not to be biased, but it's one of the sweetest finales I think I've ever seen," Cuoco said. "I don't know how someone could not enjoy this. It's very heartfelt in a time where I feel like we need – I don't know, it's just kind. Every character does have a wonderful moment."

Asked about their next steps, Cuoco said she'll be focusing on her production company, Yes, Norman Productions. "We've got a lot of stuff in development. I'm enjoying the producing hats actually. Yeah, a new path for me," she said.

As for Galecki? "Mine's coming. Don't worry."

Watch the series finale of "The Big Bang Theory" Thursday, May 16, in two back-to-back episodes starting at 8 p.m.ET/7 p.m. CT on CBS. At 9:30 p.m. ET/8:30 p.m. CT, Cuoco and Galecki will host the special retrospective, "Unraveling the Mystery: A Big Bang Farewell."