Lewis Capaldi talks about his friendships with Elton John, Ed Sheeran and Niall Horan and the advice they give him.

When Lewis Capaldi isn't on stage performing his hits, he can be found posting hilarious Instagram videos or cracking jokes in interviews — like when he told Billboard's Pop Shop Podcast in 2019 that he could "beat a lion in the mouth' because he was so happy to be No. 1 in America.

But in his new documentary "Lewis Capaldi: How I'm Feeling Now," released on Netflix on April 5, the Scottish singer-songwriter gets much more serious than we've ever seen before.

Lewis Capaldi opens up about his battle with mental health, his diagnosis with Tourette's syndrome and the "impostor syndrome" he feels about his seemingly overnight success in the music industry.

"I didn't want to do a documentary, to be honest," Lewis Capaldi said in a new interview with Billboard's Pop Shop Podcast.

“But the idea came to me and it sounded like a lot of fun. I never sat down and said, "People need to hear my story." That was not my thought process. It was never my life's ambition. But I'm very happy it happened," he explained.

In fact, he had a very different vision for the documentary when he was first presented with the idea.

“This is late 2019, before COVID. So I was thinking to myself, “This documentary is going to be awesome! I will be on stage in front of hundreds of thousands of people! I will be on tour! I will tear! My life is going to be amazing!'" she recalled.

“And then obviously COVID came along and all of that disappeared. But we were still committed to making this documentary, and I was like, 'Oh, my God, this is going to be a very, very boring documentary!'" he continued.

'How I'm Feeling Now' is far from boring though, showing fans the epic ups and downs Lewis Capaldi has endured over the past four years.

“When I saw the first draft, it was so depressing. I was like, “Am I going to die at the end? Is that going to happen here?” It was so sad. But I'm very proud of it and I'm very happy that it's coming out and people will see it," he stressed.

In the documentary, viewers also learn more about Lewis Capaldi's friendships with Niall Horan, Ed Sheeran and Elton John, who sends the singer a sweet message to reassure him that he deserves all his success.

“I had told Ed about the 'impostor syndrome' thing and then Ed told Elton - which is crazy that Ed Sheeran and Elton John are talking about me when I'm not there. And then Elton texted me, completely out of the blue," she told Billboard's Pop Shop Podcast

As for Ed Sheeran, Lewis Capaldi revealed he had "the most open and honest and really amazing conversation" with him just last week.

Referring then to his relationship with Horan, he noted that the Irish singer "became a very good friend from One Direction's Niall Horan and I love him."

“He's amazing for general day-to-day stuff. Niall is great if I want to buy a couch, you know what I mean? He's got a really good eye for interior design, Niall has,” added Lewis Capaldi.