Chris Pratt Shares the Surprising Childhood Incident That Made Him Want to Act (Exclusive)

The 'Guardians of the Galaxy' cast spilled some 'E-Tea' about their final days of filming and what they'll miss the most.

It's the end of the road for James Gunn's Guardians of the Galaxy. The final film of the Marvel trilogy opens in theaters on Friday, and stars Chris Pratt, Karen Gillan and Pom Klementieff are spilling the tea before they go out with a bang.

The trio stopped by for ET's "Spilling the E-Tea" to share memories on their emotional final day of filming, what they'll miss most about their other cast members and their favorite things about the actor who's number one on the call sheet -- Pratt.

"Your generosity, your twisted sense of humor sometimes and you're an amazing eater too," Klementieff tells the Parks and Recreation alum. "[You're] always in a good mood."

"We're saying the truth, we're not lying," she jokes to a sweetly surprised Pratt. "We haven't been paid by you!"

"You are really good at that, you set a good tone for people," Gillan added. "[It] totally, like, really trickles down. Everybody feels it from the number one on the call sheet, right?"

"That's true. I saw that with Amy Poehler on Parks and Rec," Pratt tells his co-stars. "She always had a great attitude, and attitude is contagious. You got to make sure yours is worth catching."

Pratt jokes that his desire to become an actor came from "trauma, pain, suffering [and] a lack of attention."

More seriously, the actor contributes the motivation to an incident where he got lost as a child while out with his family in Minnesota. "I was walking in the mall holding, I thought, my mom's hand. And then I just looked up and she wasn't there and I was lost in the mall," he recounts, sharing that he then wandered into the parking lot assuming his family would be there. "I started to cry and some adult stranger, by the grace of God not some weirdo, found me and brought me back. We started looking around for my family [for] what felt like ages, finally found them -- they were shopping and didn't even notice I was gone."

"I think from that moment forward I was like, 'If I'm in the room, I'm gonna be loud,'" he says. "And I'm gonna be noticed and I'm gonna make sure everyone knows I'm there just in case I get lost. They're gonna actually notice me. I really think that's why I became an actor."

"That's so interesting, I actually weirdly heard that getting lost in a mall is common for a certain age when there was like a big boom of malls," Gillan notes. "That happened to a lot of children and they're traumatized by it because they lose their parents, you know?"

After exchanging a "trauma five," the trio muses on the most emotional of the cast as production on the film wrapped but aren't able to single anyone out. "Everybody was pretty emotional," Pratt reasons as Gillan explains, "We're an emotional bunch."

"And we have a lot to be emotional about," he points out, as the film has been long considered the final installment of a beloved series. Zoe Saldana and Dave Bautista have notably been vocal about not returning for another film after Vol. 3.

"I cried on the plane," Klementieff admits, sharing that she became emotional "at a very unexpected moment."

The actress explains that she wanted to hide in the bathroom, but Gillan was occupying the room. "And then I saw Pom, like, looking at me and I was like, 'Why is she looking at me like that?' And then went into the bathroom, came back [and] everyone was around you and there were floods of tears," Gillan recalls. "I was like, 'What happened?!'"

"We just did a group hug, it was beautiful," Klementieff reveals. "Like in the movie actually."

"Wait, I missed a group hug?" Gillan realizes as Klementieff and Pratt laugh at her.

"Yeah, because you were in the bathroom," Klementieff replies before Pratt jokes that the cast likes to "save that for the moments when you're [not there.]"

"It's just emotional for us when we know when you're peeing," he adds. 

The trio reminisces over Vin Diesel's "beautiful messages" sent over the holidays, including one particular video that almost sent the cast into a frenzy searching for Gunn. 

Klementieff recalls how Diesel sent her a video message with his family, sharing, "They're all wearing white [and] it was beautiful and inspiring and I just wanted to answer something like weird, so I just replied, 'adopt me,' to make it weird."

To which Diesel responded by giving the message "a heart." But his sweet messages when awry when Gunn changed his phone number without the Fast & Furious star knowing. 

"Vin sends these videos out to all of us and friends of his where they're just emotional and moving videos of how much he loves you and I don't know if it's a thing he does to everybody, but he'll send these videos out, which feel kind of random, but are also very beautiful and earnest," Pratt explains. 

So Diesel sent a video to Gunn, "but James had changed his number so it went to a random person," Gillan shares.

"It went to someone else. And the person replied with, 'Man, I'm not doing well. In Vegas. Thinking of ending it all,'" Pratt continues. "And so, Vin called Zoe and was like, 'We got to charter a plane, we're going to Vegas to save James,' because James is outspoken about having been sober for years and years and years. So, pretty much his entire adulthood he's been sober, so he doesn't drink. So the idea that he was in Las Vegas about to end it all, Vin thought he needed to go save his life. And he chartered a jet to go to Las Vegas. And he was going to go pick up James in Las Vegas and texted Simon, the assistant for James [at the time] who's now a producer on the Guardians films, and he's like, 'What hotel's James at?' He's like, 'I'm pretty sure he's staying at some hotel in Pasadena.'"

"So someone out there got a video text from Vin Diesel and responded with some weird, dark suicide note," Pratt finishes.

"I hope he's OK," Gillan adds. "Vin was gonna come in and be like a superhero, save the day."

When Pratt spoke with ET at the Guardians of the Galaxy Vol. 3 premiere last month, he said he's still soaking up and enjoying every bit of seeing the saga's farewell film come to fruition.

"Well, I feel excited. I'm not sad yet," Pratt said. "This is our big night to celebrate, and so I'm just trying to be present. I'm trying to be involved. I'm just trying to be here, take it all in and, and see all these shining faces and these folks dressed up like these characters."

The previously released trailer alluded to Rocket Raccoon being the final film's center with flashes of his origins as an innocent animal who gets turned into what he is today through cruel experiments. 

But, as Feige said in ET's exclusive look behind the scenes of Vol. 3., the trilogy's heart lies in its found family, which is tested like never before in this new installment. "Everything that drives it is that emotional center of all these characters who are all outsiders," Gunn explained. 

"It's another rock opera. It's really fantastic and it wraps it up in a way that really only James could," Pratt concluded.

As previously revealed, the film will give fans a proper introduction to Will Poulter's Adam Warlock as the gang prepares for their heartbreaking farewells.

Back in November, Gunn told ET that the tone of the final film in the trilogy is much more emotional than any of his previous Marvel films.

"It's got the fun that we expect from the Guardians," he assured. "But it's also an incredibly serious story in some ways, where we tell the end of the story of the Guardians and the end of the story of Rocket and where he came from. We need to go back to the beginning to tell the ending."

"I think at the heart of it, it's always been emotional," he said of concluding the Guardians' story. "The Guardians journey started with a boy watching his mother die in front of him and going away, you know, running off to another place... I think that many of us, in different ways, we've escaped our childhood traumas, and gone to someplace else. And that's at the core of the Guardians story."

Guardians of the Galaxy Vol. 3 opens in theaters May 5.