Rosie Huntington-Whiteley has nightmares about being sent to prison.

The 30-year-old model - who has son Jack, seven months, with fiancé Jason Statham - thinks her scary dreams stem from a feeling that she could be ''caught out'' and isn't as confident as she seems.

She told Harper's Bazaar magazine: ''I was talking to a friend of mine the other day, because I have this recurring nightmare that I'm going to go to prison, and he said that stems from a fear of being caught out, [which] I think a lot of successful women struggle with.

''You know, men have that kind of unapologetic confidence at all times. And I think women always feel there's a sense of surprise if they get ahead in the game. Certainly for me, I always feel like it could come to an end tomorrow.

''That's what I think the ultimate drive is for me - it's that what goes up must come down, that's just the way it goes. Everything in life does.''

Rosie moved to London for her career when she was just 16, and relocated to New York two years later and will always be grateful for the ''freedom'' her parents gave her.

She said: ''My mother said to me, 'You know, darling, a great opportunity might not be there if you come back to it later. If the opportunity is coming now you must grab it while you can'... And I think the greatest thing that she and my dad ever gave me was that freedom.''

Meanwhile, the 'Transformers: Dark of the Moon' star revealed she found her early days as a model ''gritty''.

Despite this, Rosie doesn't think it would be right for her to complain about her job.

She said: ''[There was] a lot of rejection [but] I have a reluctance to say, 'Oh I work so hard', because it's not like I'm a nurse who's working 20-hour shifts with very little pay.''