Simon Cowell has admitted that he's "appalled" by things he's said to contestants on shows like X Factor.
He's known for his harsh comments to people who he thinks are rubbish, and he's even made some contestants cry.
But now TV's Mr Nasty, who's also a judge on Britain's Got Talent and American Idol, has said he sometimes goes too far.
"There's many, many times where I've watched the show back and I'm absolutely appalled," he admitted.
Simon also said that on shows with live audiences it was easy to get caught up in the mood and be too mean to people.
"You become part of a mob and when you watch the show back you realise that you've gone too far," he told Piers Morgan for an ITV show.
Simon spoke about Susan Boyle as well, who became tired and ill after she struggled to cope with the pressures of fame during Britain's Got Talent.
Susan Boyle came second in Britain's Got Talent 2009
He said it had been a "wake-up call".
"That's when you suddenly realise, 'I haven't thought about this person as a human being'," he said.
Simon then offered Susan lots of support and gave her the chance to leave the show, but he said she stayed because she wanted to.