It's hard to imagine the music scene before One Direction, the Irish-British boy group that has rapidly taken over the top spots on the pop charts, but despite their international stardom, the fab five say they are just regular blokes trying to navigate the waves of fame.
"What's happened to us in the last few years has just been mental," Niall Horan said.
"Nightline" went behind the scenes -- and in their dressing room -- with Horan, Liam Payne and Harry Styles, all 19 years old, Zayn Malik, 20, and Louis Tomlinson, the oldest at 21, on Sunday as they were getting ready for the MTV Video Music Awards -- complete with funny moments, from Styles as he hits the shower and a shot of Horan's abs.
In an interview with "Nightline" anchor Cynthia McFadden, One Direction talked about their upcoming third album and how dramatically their lives have changed in just a few short years.
Having sold 30 million records, performed at countless sold-out concerts, and taking home the MTV Video Music Awards on Sunday for "Song of the Summer" with "Best Song Ever," One Direction could be the first boy band worth $1 billion, according to Business Insider.
Despite the fame and money, the guys said they still love to goof off with other each like they would if they were "at university together," and they haven't forgotten about their humble beginnings.
"It's not about being who you were. It's about keeping who you were part of who you are now," Styles said.
One Direction was born out of happenstance on the British TV show "The X Factor" in 2010. When they started out, the guys said they barely had enough money in their pockets for bus fare. While on the show, each of the boys auditioned individually, and when they failed to make it into the "Boys" performance category, show creator and judge Simon Cowell suggested the five perform together. Within weeks, the group had started gaining popularity in the U.K.
"We're very rare," Payne said. "But we're so lucky that, you know, our personalities actually blend together so well and we're all quite easy-going."
"When we sit down, we can't believe that we get on so well ourselves," Malik added. "When we talk to each other, we're like, 'How crazy is it that we didn't know each other?'"
While they said they don't mind being called a "boy band," the five seems more like a band of brothers.
"We didn't really want to follow the stereotype of the boy band," Tomlinson said. "But we are, obviously, still a boy band. And we're just doing it in our own way."
"We literally are the best of friends," Payne said. "We hang out with each other 24/7, and we have a good time."
Having international fame doesn't come without its critics, many of whom chastise the guys of One Direction for not writing their own songs and not playing instruments.
The band disputes this, saying they wrote "the majority" of their own songs on their upcoming album -- out of 14 songs on the album, the guys said they wrote 10. Payne showed "Nightline" a tattoo on his forearm that said, "I figured it out" -- a sneak peek of lyrics from a song on their yet-to-be-released third album.
And while only Horan currently plays guitar, others said they were in the process of learning how to play an instrument as well.
"We take our music so seriously," Tomlinson said. "And especially this last record ... we have done a lot of writing on it. For us, the music is such an important part."