Jessica Chastain on the moment she defended herself against her mum's abusive boyfriend.

“I remember… my room was messy or whatever and he had taken my clothes, and I was telling him to give me back my stuff—and he slapped me.”

Jessica Chastain attributes that moment – the moment she chose to defend herself against her mum’s then-boyfriend – as a “turning point” in her childhood.

In an interview with Wall Street Journal Magazine, the two-time Oscar nominated actress shared how being raised by a single mother in a financially vulnerable household put her and her family in the position of depending on abusive men.

“We moved quite a bit, we were evicted, and there were times when we were living with my mom’s friends,” the Molly’s Game star said.

“I saw how much [my mum] struggled. Whenever a man would come into the household, it would usually lead to some sense of financial upheaval.”

Chastain went on to describe how, as a child, she found herself needing to physically take back her power from one of her mum’s partners, who she and her mother were living with at the time.

“I just kicked him in the genitals, and he fell to the ground immediately. It was me, my sister and my brother—and I remember looking at my sister’s face, and we were both like, ‘Oh, my God, what did I just do?’ And then I ran out of the house.”

The encounter was a lesson in fighting back and standing up for herself, one that has stuck with Chastain throughout her life and career.

"I always look back on that moment as knowing that, okay, if anything happens to me, I'm capable of fighting back. If you allow a bully to intimidate or victimise you, they'll continue to do it. Bullies are actually weak, they don't go after strong people."

"He never messed with me again."

Chastain uses her platform to advocate for several social issues, including gender inequality, pay parity, and sexual harassment by standing in solidarity with movements like #MeToo and #TimesUp.

LISTEN: Tracey Spicer joins Holly Wainwright and Rachel Corbett to deep dive on why the #metoo movement has kick-started a new way of thinking worldwide. Listen below...