Jim Parsons, Johnny Galecki, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik and Melissa Rauch talk with The Hollywood Reporter about the emotional ending of TV's longest-running multicamera comedy in history and preview what they're doing next.

[This story contains spoilers from the series finale of The Big Bang Theory.]

That's it.

With one last big bang, CBS said farewell to megahit The Big Bang Theory during a heartfelt and surprising hourlong series finale that featured payoffs to some of the show's long-running inside jokes (the elevator!) and a larger sense of life going on as usual for its beloved characters.

"This show started with Leonard, Sheldon and Penny meeting in a hallway, and we got to watch these people become friends and then truly become a family," former showrunner and exec producer Steve Molaro says. "And at the end of it all, nothing felt more like this group was a family than the final moments, and that means the world to me."

Amy and Sheldon won the Nobel Prize for physics. Viewers caught the very first glimpse of Howard and Bernadette's children. And, speaking of kids, Leonard and Penny are expecting. And Raj winds up befriending Sarah Michelle Gellar (playing herself) on the way to the awards ceremony. But ultimately, the series ended on a note of personal growth: Sheldon, behaving like a jackass amid his career-defining moment, realizes he has his friends to thank for his success.

"When I originally read the script, at the Nobel ceremony — when everyone stands up — I was just so amazed by the brilliant writing," star Kaley Cuoco (Penny) says. "To give everyone their moment and to have Sheldon who, after all these years, can never apologize — actually apologize — to his friends is unbelievable. And to do it in front of people and to give of himself like that was unreal."

Below, the Big Bang Theory cast talks with The Hollywood Reporter about their reactions to how TV's longest-running multicamera comedy ever ended, what they're doing next and which goodies they kept from the show's geektastic (and now former) Burbank set. Click here to read THR's deep-dive interview with co-creator Chuck Lorre, showrunner Steve Holland and exec producer Molaro.

Jim Parsons (Sheldon)

How it ended: Sheldon's journey comes to an end when, after he pushes his friends to the brink, he uses his Nobel Prize acceptance speech (which he delivers alongside co-winner Amy) to acknowledge his friends for the major roles they played in his life that allowed him to achieve his dreams.

Parsons' reaction: "Chuck Lorre once said that watching these characters change will be like watching paint dry — you wouldn't even notice it was happening. That turned out to be both true and not true. We got to play long enough that they were allowed to change and you did notice it because at some point they were writing enough episodes, like, well we have to. They have to morph a little bit. And that made it really fun. I'm deeply satisfied with how it ended."

Keep from set: "The set department was gracious enough to make us all replicas of the little placard that says 4A on the apartment. I opened that and had tears in my eyes immediately. That's been funny about closing out — it's been these little trigger moments. Like, 'I'm fine, I'm fine.' And then I'm crying."

What's next: "I don't know. I'll do the Boys in the Band movie this summer for Netflix, and then I'm just skydiving off a cliff and see where I land."

Johnny Galecki (Leonard)

How it ended: Leonard and Penny are pregnant!

Galecki's reaction: "The pregnancy shocked me. I didn't get it at first. Molaro and I talked about them maybe not [being pregnant]. We talked about relationships, and there was one in particular to his life that he felt was similar to Leonard and Penny's. And we did touch on the pregnancy topic a few times recently. But it was a larger question of, 'What do Leonard and Penny have in common? What do they talk about? And that became easier; they found a common lexicon in the last few seasons. But maybe midway through the run we thought, 'Is that [relationship] realistic? Is that realistic?' That broke my heart that it might end with them not together, but it was a discussion years and years ago. … The main takeaway is that these friendships will continue; the writers didn't want someone to move away. We wanted to leave the audience with the idea that these friendships and the love that they have continues."

What's next: "We're producing six TV shows, a film that John Carpenter is directing and a play. I'm going to let Leonard run his course through my bloodstream before taking on much of a big role. I might do one, two at the most, episodes of The Conners because I just can't stay away from those people!"

Kaley Cuoco (Penny)

How it ended: Penny's pregnant!

Cuoco's reaction: "I was super happy. I didn't expect it at all because they've been playing against it for so long. I thought they did it so well and loved how it was a surprise and she was wrapping her brain around it. I think they're going to be awesome parents. They waited so many years, and they're so fun and easygoing. Or Penny is really kind of easygoing! I think they'd be adorable parents. I can only imagine."

Keep from set: "I took two pieces of art from the living room. Behind the bookcase there are these two robot prints, and I took those."

Simon Helberg (Howard)

How it ended: Howard and wife Bernadette take their first trip away from their kids — who are seen for the first time in the series finale. Howard winds up missing his children more than anticipated, and it delivers a strong message of how happy and fulfilled he is with his family.

Helberg's reaction: "It's a sense of life goes on because this show is going to be on like a hundred times a day and in every airplane."

What's next: "I'm going to do some theater in the fall. I need to play different characters that maybe wear looser pants and spread my wings — and my legs apparently — which I haven’t done for 12 years."

Keep from set: "I took a Nintendo controller belt buckle that Howard wore in the pilot. It resonated with me."

Kunal Nayyar (Raj)

How it ended: After Raj and Anu's breakup, Raj winds up sitting next to Sarah Michelle Gellar (with the Buffy grad playing herself in the ultimate finale cameo). While Raj never found his "person," there is a sense that he'd never stop trying to find love.

Nayyar's reaction: "The idea is that the show continues. We, as the audience, finally say goodbye to the guys, but the guys wake up the next morning and they go to work and they get Chinese food on Monday and Raj still probably stumbles. I think it's a beautiful, beautiful way to end."

What's next? "Retirement! [Laughing sarcastically]"

Keep from set: "I haven't taken anything yet. I wanted to take Frodo's sword from Leonard and Penny's apartment, but it wasn't there so I didn’t take anything. But I'll figure it out."

Mayim Bialik (Amy)

How it ended: Amy and Sheldon win the Nobel Prize in physics. After receiving attention from the press, Amy — with Raj's assistance, naturally — decides to get a makeover.

Bialik's reaction: "I had been wanting to cut my hair; nine years of having it straightened had damaged it and it felt good to do it that way. We really got to see a different side of Amy in a lot of ways. Our writers took Amy's character to a lot of places we haven't even had her go. These last two episodes see her have a new look and really embrace that, even despite Sheldon's reaction to it. It's very big to have a woman so prominent in science on the show, and that's really powerful and hopefully impactful. There's a lot of sweetness and a lot of depth to our finale and that's to the credit of our writers. People will feel good knowing what Amy and Sheldon went through and how it ended. And also how the friendships are really the enduring message of this episode."

What's next: "I have a screenplay that I wrote that I'm planning to direct so we're trying to get that going. And I have a couple projects I'm on as a producer and some acting stuff we're working on."

Melissa Rauch (Bernadette)

How it ended: With a loving and devoted — if not a little creepy — husband, two kids (whom viewers see for the first time in the finale), a successful career and a sense of life going on.

Rauch's reaction: "I thought it was so gorgeous to see their kids onscreen. The small moments of this show — Howard and Bernadette spending time together with their kids and the emotional core of everyone's friendship together — really is what sustains so many of these storylines. The fact that we have this beautiful moment of just, "This is them, this is the heart, this is why we tune in is the core of this family" — it kills me."

Keep from set: "I took Bernadette's glasses. I didn't know that I was going to and then the night of the finale taping, I realized that it was the last time that I was going to wear them and the last time that I was going to be speaking in that voice and I got very choked up and thought, "I have to hand these back!" And then they allowed me to take them home."

What's next? "The Bronze 2 would be really fun. We're working on a couple writing projects and I'm looking forward to spending a bit of time with my family before I figure out the next thing."