I always had a very strong sense of responsibility, so the minute I started to work in fashion, I was always tremendously serious-too much sometimes. Of course, you can make a lot of mistakes in this job-I still do-but you need to limit them as much as possible. When you're responsible for such a huge company, you cannot play too much. In the beginning, I was working 20 hours per day and I was going crazy. I learned that I needed to delegate and to trust the people around me, but there is still not one element that I don't see or edit or discuss with my people.

I think the '70s are always inspiring to me. I was born then, so I have a lot of memories about how my parents were and what kinds of movies I was watching.

I always loved the look of musicians. I've always admired them because they have a look - when I was growing up, it seemed that the ones I liked didn't need to have a stylist.

When I approach a collection, I never think too much about myself, because doing fashion and being a designer, you need to dream. Of course, there's always a part of myself. I'm always wearing what I'm doing. I'm not a party girl, but when I have the opportunity to go out and dance and be crazy for a night, that's the fall/winter collection.

I think the simplest way to break the ice is probably to try playing on the same level, to discuss everything in normal life. So, for example, with Katie Holmes, we just spent one hour talking about her daughter. Or with Madonna, when we were working on the event in New York, we spent hours deciding every single aspect together, from the dishes to the flowers to the cards.

All the drawings and sketches and clothes of Yves Saint Laurent in the '70s were so colorful, so bright.

I inherited this collection of vinyl records, which at that time numbered 6,000, and I've since continued to collect music. As you know, vinyl records can be very heavy, so every time I have to move into a new house, I need to build a complete new wall of shelves to put all these records, which is a nightmare for the architect.