Simon Cowell wasn't sure he'd be a "great dad".
The 57-year-old music mogul admits he never realised how "incredible" it would be to raise a family until his girlfriend Lauren Silverman gave birth to their son Eric three years ago, and he won't rule out having more kids in the future.
Asked about the prospect of another child, he said: "Look I wouldn't say no, but I had no idea (with Eric) . . . it wasn't planned.
"I think if I'd have sat here four years ago and said to you, 'I'm going to be a dad' it would have been like, 'Yeah right'.
"And even if I'd have said yes, I would have said at the time I'm not sure I'll be a great dad because I just don't know what to do.
"Then the most amazing thing happens.
"That after about a year and a half you create this connection and it's very difficult to describe. You always think the biggest love you'll ever have is for your family and for your parents.
"You don't understand what it is like to be a mum or a dad until you have a son or a daughter.
"It is beyond anything I have ever experienced. It is quite incredible. It does make you, I think, a happier person."
The 'Britain's Got Talent' star insisted he has never "planned" anything in his life, so refused to admit whether or not he'll marry Lauren in the future.
Quizzed by Dan Wootton for The Sun's 'Bizarre Life' podcast, he said of the prospect of tying the knot: "I think with anything in life just let things happen rather than plan.
"I'm saying that all the good things that have ever happened in my life I've never, ever planned.
"I genuinely mean that. From when I left school at 16 I didn't know what I was going to do, I just promised myself I will not be bored when I'm older.
"I'm not going to join a golf club and I'm not going to have horrible dinner parties. And I've kind of succeeded on those.
"And like I said about Eric, I hadn't planned to be a dad but I wouldn't change anything. That's it, that's a good swerve."