In 2022, Guy Sebastian spent several days in court testifying against his former manager, Titus Day.

By night, he was performing on stage in front of a sea of fans.

“I’m going from the witness box and I would get on stage, and I would see fans in front of me,” he tells ABC iview’s The Assembly.

“And it was like the best and the worst in a day,” Sebastian says.

Sebastian became an instant pop star after winning the inaugural season of Australian Idol in 2003, going on to release 10 studio albums and win seven ARIA Music Awards.

Since then, he has represented Australia at Eurovision, placing fifth with his song Tonight Again in 2015, before going on to become a judge on X-Factor and The Voice.

Guy Sebastian competed in Eurovision in Vienna, Austria. (Reuters: Leonhard Foeger)

He is also one of six high-profile Australians interviewed by autistic journalism students on The Assembly.

In the interview, Sebastian opens up about the impact of the court case.

Day had been Sebastian’s manager for more than a decade when the pair split over a financial dispute in 2017.

In 2022, a NSW District Court jury found Day guilty of misappropriating funds after embezzling more than $600,000 from the singer, but the convictions were quashed on appeal.

A retrial was ordered, and in July, a jury acquitted Day of four charges and remained hung on most of the allegations. The case was dismissed.

A civil trial between Sebastian and Day is expected to resume in the Federal Court.

Guy Sebastian gets emotional on The Assembly. (ABC/Helium Pictures)

Sebastian says it was his song Before I Go that helped him navigate the tough time.

Sebastian sings: “Just one more thing before I go / Before the final curtains close / There’s no tellin’ what comes next / But these tired hands will show / You’ll know my name before I go.”

The 43-year-old said he was moved with every performance, standing on stage singing every word “like I meant it”.

“It’s like a fight song, I guess, that I wrote during a really tough time that I go back to very often.

“I just needed a bit of a reminder that no-one has power over me to decide how big I can dream or where I can go in life.”

Since the court case, Malaysian-born Sebastian says he has been intentional about where he directs his energy, particularly on social media.

“I remember I responded to a troll on social media, and someone said something awful to me, and I sent them a message back,” Sebastian says.

“One of my fans wrote to me, and she said, ‘Guy, I’ve sent you over 100 messages saying I love you and I support you … I’ve never had a response, yet this troll who doesn’t follow you throws shade at you and gets your attention.’”

Guy Sebastian says he now cherishes his fans more than ever. (ABC)

He says the encounter left him in tears.

“I almost felt this deep shame of where I was directing my energy, and our energy is precious. We only have a certain … amount of it.

“I think it’s a daily reminder to wake up and think, ‘Am I going to devote my energy to the people who love me? Or am I going to waste it on people who aren’t in my corner?’”

Becoming the first Australian Idol

It’s been more than two decades since a 21-year-old Sebastian claimed the Australian Idol title, and a legion of loyal fans have stuck with him in the years since.

He has been awarded multiple, publicly voted popular artist awards over his career and was recently inducted into the South Australian Music Hall of Fame.

A loyal fanbase supports Guy Sebastian. (AAP: Paul Miller)

But at the beginning — when he found himself in the 2003 Australian Idol final with Shannon Noll as his competition — Sebastian was surprised by his popularity.

“I came [to Australia] when I was six-and-a-half years old … and I was standing next to this sheep-shearing country boy that’s singing country rock, had a Southern Cross tattoo.

“And at the time, I do remember there were people saying, ‘Oh, Shannon’s more the typical Aussie Idol’.”

Guy Sebastian and Shannon Noll made history as the first Australian Idol finalists. (Reuters: Edwina Pickles)

Sebastian thought Noll was going to win “by a long shot”.

“When you’re listening to the noise of what people are saying a true Aussie is, it gets in your head a little bit,” he said.

“[Then] suddenly, there were people wearing Afro wigs and camping outside my parents’ house with ‘go the fro’ signs.

“It really did change my life.”