Simon Cowell has advised students to be "useless" at school but to then "get lucky".
The TV mogul - who is said to be worth more than £200 million from his record labels and talent shows - said he didn't apply himself in lessons as a youngster, but worked hard later, and admitted being in the right place at the right time can determine success
He told US radio station Z100: "I didn't work hard when I was at school. I left at 16 and I didn't have any qualifications
"I was useless. The secret is to be useless at school and then get lucky."
The 54-year-old star made lots of mistakes when he first went into business - famously having to move back in with his parents when he went through a rough patch - but he is glad of his failures because he learned from them.
He added: "You make a ton of mistakes in the beginning and just hope you learn from them."
However, Simon has been slammed by education campaigners for his "dangerous" advice to school pupils.
British politician Michael Pavey says education is "vitally important" and thinks 'The X Factor' boss - whose girlfriend Lauren Silverman is due to give birth to their first child in February - is setting a bad example.
He said: "I think Simon Cowell has been lucky. It's one-in-a-billion that gets a chance like that.
"The rest of us need to work hard with our teachers. Anything that demotivates young people from making the best of themselves is unfortunate."