Carey Mulligan has a "crippling" fear of her own mortality.
The 32-year-old actress - who has a two-year-old daughter, Evelyn, with husband Marcus Mumford and gave birth to their second child four months ago - admitted she often gets overwhelmed at the thought her children will one day have to learn to cope without her being around.
She said: "[I'll] have a huge mortality crisis and get terribly upset that one day [I'll have to] leave my children behind.
"That has crippled me a couple of times since I've had kids: the notion that one day they'll have to be without me."
But the 'Mudbound' actress admitted becoming a parent has given her a new perspective on life and she no longer worries about small problems.
She told the new issue of Britain's Harper's Bazaar magazine: "It doesn't matter if your dress looks bad or if you can see the outline of your Spanx... It's just such small potatoes, you know?"
And the 'Great Gatsby' star's new outlook helped her when she suffered a fashion disaster when breast milk leaked out onto her dress at a high-profile glamorous event.
She said: "Back in the day, I would have been in the bathroom in tears.
"I would have been trying to leave. But it was just kind of funny. It was so ridiculous. I thought, 'If I've got breast milk coming out of my dress, then that just shows what it's like to be a working mother in the 21st century. Whatever.' "
Carey used to feel uncomfortable about her body but after going through pregnancy and birth, her attitude has shifted.
She said: "I think all that stuff has got easier. Your body has a totally different function. I've always been funny about my legs and I won't wear anything above the knee. I hate my thighs."
The British actress gained an appreciation for her curves when a friend of hers asked her to hold her baby a few years ago.
She recalled: "She was sitting in my lap and I thought, 'If my legs were really bony and skinny, that would be really uncomfortable and actually it's quite nice for this baby to have a comfortable place to sit.' "