The singer told InStyle magazine in the US: 'The first time I went to a couture show, I cried. I thought, 'This is my world - where have I been?''
She also admitted she is in a privileged position. 'I watch Project Runway and there are these people trying to do fashion shows and I think, 'How did I get into this?' It's so amazing that I have three fashion lines.'
But while fashion is her love, it's not her toughest gig. 'Being a mother is probably the most challenging thing I do - the responsibility of it is very heavy,' she admitted. 'It's the only thing that matters!'
Gwen also insisted that the only reason she rarely talks about husband Gavin Rossdale is because of his love for privacy. 'Everyone knows I love him - he's awesome,' she insisted. 'But it's private, and I would rather not get in trouble!'