You've just written a memoir, The Woman I Wanted to Be. So are you now the woman you wanted to be?
You know, the truth is, I became the woman I wanted to be very, very early in my life, I think in my late 20s. The wonderful thing is that I became that woman through designing the [wrap] dress and through its success. I was becoming this woman because of fashion, because of my little dress, and as I was getting more confidence, I was also sharing my confidence with other women through the dress. From the very, very beginning, it was this incredible dialogue with other women ... an extraordinary adventure.
The wrap dress is 40 years old this year and it's still your most famous creation...
This little dress I took for granted, even though it had paid for everything I had - the houses, my children's education, everything! I never sat down and realised the impact of it. For a while, I lost the personality of my brand and a little bit of confidence. It was only last year I decided I would celebrate this brand through an exhibition [The Journey of a Dress]. I didn't want to call myself a designer for so long and all of a sudden, I realised, I did more than a fashion statement with this dress. I did a sociological statement. The truth is, this book is so meaningful for me because I've never gone to therapy and this book was like therapy.
You write movingly about your mother, Liliane, a Holocaust survivor who was sent to Auschwitz because of her work for the Belgian resistance. You say she taught you not to feel frightened. Do you ever feel fear?
No. I was never allowed to be afraid. She would never let me be afraid. It was part of the biggest gift she gave me. She would say: "Why are you afraid? That just makes it worse." Fear is not an option. It just isn't. You've got to deal with whatever.
Was she proud of you?
Oh yes. She only died 14 years ago, so she saw me as a full woman and she saw my children as parents. Yeah, she was proud of me but she would tell other people more than she would tell me. One of the great things about this book is that I think I honour her. Two days ago, I received an email from a 90-year-old who was also a survivor of the camps - a beautiful, strong, positive woman - and she emailed me because she'd read the book and she said: "I want you to know you not only honoured your mother, you honoured all us survivors."
You confess in your book to an "infatuation" with a girl and also mention that people said your husband, Barry Diller, had never been with a woman before you. Do you think human sexuality is more fluid than we sometimes admit?
I think a lot of women have had infatuations with women. I don't like categories. I certainly love men [laughs]. I certainly have had a lot of men. I am happy that I didn't hold back and yet I never lost myself. I had a lot of fun, but at the base, I was a serious person.
Your friend Andy Warhol photographed you. What was he like?
He was a voyeur. He never spoke much. He would take your picture and say: "Oh great, that's great." He certainly was a visionary in terms of where the world was going, in terms of branding, icons ... He would have lost his mind on social media.
Are you on social media?
Yes, I always joke that I'm happy I'm old enough to have been to Studio 54 and young enough to be part of the digital revolution. I love it. I do everything on my iPad - Scrabble, jigsaw puzzles ...
I read somewhere you had a hand in the actress Anne Hathaway's conception...
Yes! I was hosting this dinner and Anne Hathaway introduced me to her mother and her mother said: "I'm going to tell you something even she doesn't know. I seduced her father wearing a wrap dress. In fact, she may have been conceived in one." The funny thing was that Anne then said: "Is that the one with the tulip print?" Her mother had kept it!
Do you have a favourite DVF wrap dress you wear all the time?
I don't have the waist to wear a wrap dress any more.
• The Woman I Wanted to Be (Simon & Schuster, $32.99).
- The Observer
