Justin Timberlake Says Leaving 'NSYNC Was One Of His 'Best/Worst' Decisions

Singer opens up about going solo on 'Oprah's Master Class.'

Maybe that epic VMA reunion got everyone feeling nostalgic, but more than a decade later, people are still wondering why oh why Justin Timberlake left 'NSYNC.

So now, four solo albums after the fact, he's clarifying on why, exactly, he decided to go solo at the age of 21.

"I would wake up every morning feeling this more and more of an urge to step out on my own and try my own hand as a musician just by myself," Timberlake said on Sunday night's season premiere of "Oprah's Master Class" on OWN. "It was happening all around me: 'Why wouldn't you ride this out? You're the biggest group in the world. Why would you walk away from this?'"

Before announcing their "temporary" hiatus back in 2002, the boy band had achieved unparalleled levels of success -- No Strings Attached is among the top 10 best-selling albums since in the SoundScan era, and they have sold more than 50 million albums. Which is why, Timberlake says, his decision was a "bittersweet" one.

"It's one of the best/worst things that I have ever done," the "Suit & Tie" singer added. "It was hard to say goodbye to that era, but I felt it changing. I felt music changing. And I felt myself changing."

So for anyone still desperately hoping for the band to get back together: Sorry, but in the meantime, watch this, and think of old times: