As told to Bibby Sowray
I remember swearing to myself as a little girl that I would never wear jeans.
Growing up in the '80s, everyone was in Levi's 501s. It was the same cut for men and women, worn with a pair of Converse and I used to think it was the worst combination possible. I think differently about denim now, of course.
I was born at the end of '82 and at that time my mother [Jane Birkin], my father [director Jacques Doillon], and three of my sisters, Kate, Charlotte and Lola, were all wearing jeans - it was all they ever wore, with a white t-shirt or a denim jacket. I must have believed that jeans were an absolute uniform.
When my mum had me she had run away to a very Bourgeois part of Paris - the 16th arrondissement, which is extremely boring. She'd left Serge [Gainsbourg] for my dad so, to hide from the press and madness of it, they bought a house in this horrible area where everyone wore two-piece Chanel suits with dreadful heeled ballet pumps and tights. My mum really stood out because she was absolutely androgynous, which today is the norm but back in the '80s it wasn't. I used to hate her for it.
Because jeans became something of a family trademark, I definitely wanted to rebel against them.
Because jeans became something of a family trademark, I definitely wanted to rebel against them. When I was a teenager I had dreadlocks and piercings and I used to walk around Paris barefoot with my flared jeans dragging along the ground, reading William Blake aloud.
People were horrified. It was great; at least they weren't saying 'Look, it's Jane Birkin's daughter'. Most 'kids of' are just 'kids of' so I created this kind of Christmas tree look that was the best way of getting out of this 'chic' character impressed upon me, which I wasn't - I was weird and tall and crooked and loud so I had to own it one way or another.
I can't say I've learnt any lessons from my mum when it comes to denim, or even style in general. She has no fashion sense whatsoever, that's why she can be a fashion icon. I remember having a conversation with Kate Moss about it; what most people don't get today is that everybody is so bloody self-conscious and trying so hard - 99% of Instagram is people trying desperately hard to resemble girls like my mother - but she had no clue about either her beauty or her sense of fun and literally just wore whatever was around.
At the time my mother had three kids, was performing nearly every night, drove her own car, barely had a nanny, and needed to wear something practical. I've never seen her in heels because she's always late and needs to run.
There's a wonderful photograph taken by Jeanloup Sieff a short while before he died, of me, my mother, Kate and Charlotte in which we're all wearing jeans. I was about 14 and had started liking them again. I used to buy them from thrift stores and tear them up the side to add a flare, an old technique that my mum had taught me.
Last time I was going through her trunk of old things I found this horrendous pair with a huge heart patch on the arse that she'd made in the '70s. I've got another pair of my mum's from the '80s, which I seldom wear but love having around. They're very of the decade, very high-waisted and short on the leg. People wore them so high and it made the most insane bum.
I don't customise my jeans anymore, which is sad. I used to do it a lot. It's the real sadness of comfort and wealth; now that I have a dressing room. I have lost a lot of my sense of style. I always tell kids: you've got it all when you haven't got much because you have to get your brain going. The more books you have the less you read, the more clothes you have the less you wear.
I remember my father wearing the same jeans for months. We would tell him to wash them but he'd say no. That's the whole point of jeans; they were made with a double grid of thread so that they're extremely resistant. I also recall him telling me that when he was younger he worked for two years to be able to afford a pair of jeans.
I used to buy them from thrift stores and tear them up the side to add a flare, an old technique that my mum had taught me.
It's funny, despite being French, until a few years ago I'd never made the connection that 'denim' is actually 'de Nîmes', as in the city of Nîmes, where it came from. There's something beautiful about this story of this crazy fabric which you can really, really have fun with – and now you have Vetements, a brand which can do insane pieces of denim, and then on the other side you have the jeans of J Brand, a company I now work with, that are just so super classy and chic.
To me, denim is a form of protection. When I am on tour with my band, TK, I take one black pair of jeans and one blue pair. They're like a second skin and I think that's why a lot of musicians wear them. You want people to forget the look and just listen and jeans and a t-shirt is this kind of code where one can forget about all of that and concentrate on the music.
As a kid I hated wearing denim dungarees, but now when I see all the pictures I think they're so lovely. I even forced my son, Marlowe [now 15], to wear them when he was small. They're like Marmite, people either love them or hate them. The drummer in my band has a pair and I love it when he wears them, but the rest of our group just takes the piss. I guess it makes me think of children, and I love the practicality of them, there's something really beautiful about that.
I own around 10 pairs of jeans, but it's the same three I wear until they crack, or that terrible moment when the zip just doesn't work anymore. There's something extremely personal about how we feel good or not in a pair of jeans - a lovely pair that fit you perfectly are hard to find.
In fashion, we're always going back to something and now we're going back to the 80s, which was the era of denim. It was this uniform that went through every age, every country, every social level. It was the first democratic style – men, women, kids, even my grandmother had a pair - everyone had jeans. There's a beautiful message behind that and I think that's what we're craving right now.
Read more from our denim special in the April issue of ELLE UK