Sheena McKenzie and Phoebe Parke, for CNN

British actress Emma Watson made an impassioned plea to women around the world: "Don't let anyone tell you what you can or cannot do, or cannot achieve.

"Just don't allow it. It's wrong. It's so wrong. Be what you want to be -- and prove them wrong."

The emotional Harry Potter star took to the stage at Facebook's headquarters in London on Sunday, March 8, to talk about gender equality as part of International Women's Day celebrations.

CNN was among the live audience of around 150 people -- with millions more watching the live stream across the world --as the 24-year-old UN Goodwill Ambassador spoke about her own feminist journey.

Emma's Facebook moment

Of the dozens gathered at the event, the majority were bespectacled young men -- not so unlike Harry Potter himself.

Describing the "surreal" moment she gave a speech at U.N. headquarters, later watched by 17 million, Watson said: "Gender equality historically has been a woman's movement.

"And how it's affecting men hasn't been addressed," she told moderator Greg James.

During the hour-long conversation, Watson gave the audience a rare glimpse into her private life -- and the difference between chivalry and sexism.

"I love having the door opened for me, isn't that just polite?" she said. "But I think the key is, would you then mind me opening the door for you?"

"Chivalry should be consensual."

And it's not just women affected by gender inequality -- men suffer too, she added.

"I get disturbed by this idea that men can't cry," she continued.

"They can't express themselves and I think that's the saddest thing in the world. Being able to express yourself is what makes you human -- it's not what makes you a girl."

When internet trolls threatened to release naked photos of the actress, following her UN speech, she said it only made her more determined in her campaign.

"If they were trying to put me off -- they did the opposite," she added.

Almost 230,000 men and boys across the world have since joined the HeForShe campaign, including U.S. President Barack Obama, and actors Joseph Gordon-Levitt and Matt Damon.

"I read a letter of support from a 13-year-old boy that was equally as passionate as a CEO," said Watson, adding that she often read their stories before going to bed at night.

"I asked my younger sister: 'What would be the one thing you'd want from boys in your life?' She said: 'I just want them to play with us.' And I think that really translates at every level. We just want to be included."

Watson also talked about the inspiring influence of her mother, Jacqueline, who was a "single working mother and type one diabetic.

"She wanted me to be my own person and said a bit of rebellion was good," said Watson, adding: "She was actually thrilled when I got my first detention... I think I failed a Latin exam."

Answering questions submitted via Facebook, Watson said the recent lack of female representation at the Academy Awards showed that the fight for gender equality was far from over.

"Why are women not directing their own stories?" she said.

"The human race is a bird -- and it needs both its wings to fly. And at the moment one of its wings is clipped," said Watson, paraphrasing famous American feminist, Gloria Steinem.

When asked what things we can all do to affect change, the actress said it wasn't necessarily about grand actions -- but small ones.

"It's everyday, it's individual, it's on a case by case basis," she said.

"Whether it's speaking up or trying to change the way someone else thinks about an issue."

In the audience, a man wearing a Hogwarts jumper asked Watson whether women should be paid the same as men, when they are more likely to take maternity leave.

She answered: "I don't think in the grand scheme of things [maternity leave] is going to hinder a woman being incredibly effective in her field.

"I think men should be equal partners in raising children."

CNN