For Billie Jean King - surely the greatest activist in the history of sport - the sense that a movement is building is undeniable.
After a summer in which the World Cup became the most talked-about event on the planet, and stars like Megan Rapinoe used their platform to challenge the male elites, King senses echoes of the 1960s and 70s when she first starting shattering pre-conceptions about women’s sport.
"I think we’re having a wave of women’s sports with things like the World Cup," she tells Telegraph Women's Sport. "We’re having a second wave - it’s in the air.
"But the thing is with history is when you read it, it’s fast, but when you live it it’s like a slug. Two feet forward, five feet back. Young people can’t understand what happened before. It’s important to have history but you have to keep going because there are always struggles in every generation."
Despite her frustration at the progress of the fight for equality, King’s optimism around the overall direction of travel is well founded. The emergence of strong role models like Serena Williams, and the brave campaigning of American athletes like Alysia Montano and Allyson Felix this year in calling out Nike for their maternity policies has been a collective major step forward for women's sport. The world's best footballer Ada Hegerberg, who boycotted the World Cup in protest at how women's football is treated in her native Norway, gave voice to the growing momentum when she said in May: "It's impossible to be in football and not fight for equality."
Observing these women and their powerful voices in the fight for equality, King says: "You can speak a lot more candidly now, whereas previously you couldn’t say a lot of stuff."
King, now 75, would know this better than anyone - having dedicated her life to campaigning for equal rights. In the 1960s, as the best tennis player in the world, she helped lay the groundwork for a women's tour, which led to the creation of the Women's Tennis Association (WTA) that still governs the sport, in 1973. That same year, she defeated avowed chauvinist and former Wimbledon champion Bobby Riggs in Houston, in what was dubbed "The Battle of the Sexes".
King retired from tennis in 1983, having won 39 grand slam titles, 12 of them in singles. Two years earlier King's homosexuality was revealed by her lover Marilyn Barnett, which led to sponsors withdrawing their endorsements and the end of her marriage to Larry King. She is now in a long-term relationship with former world doubles No 1 Ilana Kloss, and in "retirement" has dedicated herself to campaigning for equality - in the process becoming a totem for women's and LGBTQ+ rights. A decade ago this was formally recognised when President Barack Obama awarded King the Medal of Freedom - the highest civilian award in the United States.
Ten years on plenty has changed in the fight for equality, but how does King believe modern-day activists can best use their platform and voice?
"You have to keep speaking but most importantly you have to actively listen," she says. "That's if you want to be a great one that lasts. To have a lasting imprint not just a little shock one that has an impact for a day."
King is too restless, too modest to ever describe herself in those terms, but it is undeniable that she has been a "great" activist. As for her impact, it has already lasted not just days but generations. She is also one to practise what she preaches about the importance of listening - during our conversation King is constantly asking me questions, voracious in her thirst for knowledge as we speak at an event co-hosted by the All England Club, the Billie Jean King Leadership Initiative and Pride Sports to discuss issues of sports, sexuality, empowerment and individualityand curiosity about the opinions of others.
Once activists have learned to appreciate the importance of listening, King stresses that they must mobilise, and stop accepting being treated as second-class citizens: "We have to have more and more activism. For women, look at how few opportunities we have.
"Women need to organise. Organise, organise, organise. The women's football team in the US is the team, it’s not one person. We find power in numbers, and you find support in one another. And you need to get people around you that are good - good lawyers etc. It’s a lot of work. To get people to change and give up the power and money they have, it’s hard.
"And the thing is girls are supposed to be grateful for crumbs. Haven’t you ever noticed that? Oh you must be so happy because we gave you something? Guys would never be like that, they’d be like: are you kidding? That’s what women need to be like."
A particular source of frustration for King is the way women footballers are treated by Fifa - echoing Rapinoe's public criticism of the World Cup's scheduling and relatively paltry prize money.
King says: "First of all, you could go through every single sport and ask about what are the opportunities for women? It’s apples and oranges when you talk about women’s sports.
"Comparing women's football to men’s is crazy. When did they start men’s football? The 1800s. That’s the way we should be talking about it. We are second in the market place, but if we had the same investment over the years, and enthusiasm then we would see real change.
"Fifa give us a little, but that’s like putting us on a drip. Start giving 50-50 to the men and women, because where are the growth opportunities? With the women. Are organisations going to have to invest in the women like they did with the men a thousand years ago? Yeah, but they don’t want to do it. Women’s sports is in its infancy, and women’s tennis is the lead."
King's pride at her former sport's progress is tinged with frustration that tennis is not more accessible. She is excited by the revamp of the Fed Cup, but would like to see an end to best-of-five set matches, and a more widespread introduction of sudden-death deuce points rather than the current "advantage" system. "People have lives besides looking at us," she says. "It needs to be shorter."
Of her own place in tennis history, King says that winning titles always came secondary to fighting for equality: "Oh I didn't worry about my tennis at all. Twelve singles grand slams was a joke, really."
That campaigners like King have had to sacrifice their own careers in the fight for progress is a damning indictment of the secondary role sportswomen have often been forced to play. Hegerberg's ongoing conflict with the Norwegian FA suggests similar dilemmas still exist, while King herself conceded last month that Williams would stand a greater chance of winning a 24th major title if she spent less time campaigning for equal rights.
Above all, King wants fairness and acceptance. She winces at the way Caster Semenya has been ostracised, and echoing her appeal for activists to listen, says that judgements cannot be made on intersex athletes like Semenya until we have more information. King admits to disagreeing with her good friend Martina Navratilova, who said in February that allowing transgender athletes to compete in women’s events was "insane and cheating".
King was so moved by the debate that she consulted an expert scientist on the subject, who told her that Semenya should be allowed to compete because there is not yet enough information.
The inclusion of transgender and intersex athletes will be one of innumerable challenges facing women's sport over the next few decades. For King, despite all the obstacles she has faced, there is optimism that the fight for equality is moving in the right direction.
"It's going to continue now," she says. "There’s movement, and times have changed. Women are speaking out more, men are supporting us more than ever, and I think that’s all going to lead to positive changes.
"Freedom and progress can go away immediately. You always have to know it’s in a tenuous position and keep moving forward. We need every generation to be activists, and nowadays everyone’s an influencer so you never know where the inspiration is going to come from.
"And if progress slows down again, well that will be another challenge we have to overcome."