Ozzy Osbourne: From Prince of Darkness to reality TV's favourite dad

"Being able to see someone who's a superstar... in this somewhat relatable context was new and refreshing, because it's not like people were following Ozzy on Twitter," Dr Lindemann said.

That kind of real-life access took its toll, as Ozzy told Metal Hammer in 2022 that he felt like a "laboratory rat" after spending three years with cameras following him around, though he said he was "not ashamed" of the programme.

"It got to the point where I was falling apart emotionally," he told the magazine, "because you can't... relax".

Spending their teenage years in the spotlight also wasn't without difficulty for Jack and Kelly, who wrote about her struggles with drug use in books released in 2009 and 2017.

"I don't think either one of us was really prepared for" the fame, Kelly told ABC's Good Morning America in 2017.

"That's a difficult situation to put teenagers in. But they handled it as well as anybody could," Mr Stilson said.

After 52 episodes across four seasons, The Osbournes finally ended in 2005. But Mr Stilson wonders if they should have ended production after the first season. It became a "darker show" after that, he said, as Sharon was diagnosed with cancer and Ozzy "fell off the wagon" with drugs and alcohol.

For Mr Kramer, part of the appeal for audiences was Ozzy's "regular folk" working-class background - and for Americans, a fascination with Ozzy's "heavy" Birmingham accent.

Ozzy seemed to embrace that hard-scrabble British persona who appeared on US screens.

"You know, when they show it in England, there are no bleeps (over the swears). It isn't as much fun," he told Rolling Stone in 2002.

Mr Stilson doesn't believe that hard edge is what made the show successful.

"The success of the show was the sweetness of the family and the ridiculous dynamic," he said.

"It was about a functional family - that cursed a lot."