LOS ANGELES, Sept 1 — Justin Bieber’s performance may have been one of the highlights from this year’s MTV Video Music Awards on Sunday, but the Internet has been ablaze with speculation as to why he broke down in tears onstage after it ended.

The Canadian singer delivered an impressive, high-energy performance, starting with summer hit “Where Are U Now,” and ending with his latest single “What Do You Mean?” — even taking flight at one point.

But as he received a standing ovation from the star-studded crowd, the Biebs struggled to compose himself and burst into tears.

Host Miley Cyrus seemed at a loss for words as she tried to move things along and was left just repeating, “Wow.”

A source close to the Biebs said that he was just plain overwhelmed because he ‘worked so hard not just on the performance but himself.’ — Reuters pic

So what went wrong during the Biebs’ return to the MTV VMA stage for the first time in five years?

According to an unnamed source, who spoke to Gossip Cop, it was actually a case of things going right for the 21-year-old singer who has been lying low of late in an effort to reassess his life.

The source said Bieber was just plain overwhelmed, saying “He worked so hard not just on the performance but himself. He didn’t know how people would accept him. When he saw them on their feet cheering, he was overwhelmed.”

The source also noted, “Last time, he was on an award show he was booed. This time he was cheered for. It meant a lot to him.”