Four years ago, a teenage girl changed my life in one conversation. She was 13 years old, she was a friend's little cousin and she casually told me that she had met the man she was going to marry. So I said, "OK, tell me about him." And she told me that his name was Harry Styles. (Laughter) So I laughed a little, like you, and then she said, "I know you don't think I'm serious, but I'm actually going to be with him. Because I love him so much that I would slit someone's throat to be with him." (Laughter) And that was the moment that I became obsessed with fangirls. I didn't know it then, but that moment would transform the course of my life and go on to change everything that I thought I knew about being an adult, being a woman and being truly happy. But before we get started, what is a fangirl, and what is a Harry Styles? Well, according to the dictionary, the Merriam-Webster dictionary, a fangirl is a "girl or woman who is an extremely or overly enthusiastic fan of someone or something." Technically, you can have fangirls of anything, but my specific interest was in fangirls of boy bands. Because of their somewhat lethal reputation. I remember, my dad had told me this story of some Beatles fans in the '60s, who apparently had torn a parked BMW to literal pieces, because the band had supposedly just been sat in it. In the '60s, the Beatles were the biggest boy band on the planet, but when I met this girl in 2015, the biggest boy band on the planet was none other than One Direction. And Harry Styles was a member of One Direction. Harry Styles was reputed for his compassionate demeanor and perfect hair. I learn this when I read thousands of tweets about him. I learn that he is a sweet cupcake. I learn that he is a perfect angel. I learn that one time, he vomited on the side of a freeway in California and that within two hours, fans had turned the site of the vomit into a sacred shrine. (Laughter) I scroll through -- (Laughter) I scroll through fan-made paintings of Harry, baby photos of him, paintings of baby photos of him. I watch videos that show me how to make DIY love totems for Harry -- for example, a lampshade covered in photos of his face, or a key ring that states the exact time of his birth. I read hours of fan fiction, and I fall down this specific rabbit hole of stories that actually place me as a protagonist inside of various imagined romances with him. So in one, I tell him that I'm pregnant with his child. In another, we meet in hospital where we're both fighting cancer, and in another, we fall so deeply in love that we become fugitives who kill people. (Laughter) But then ... something unthinkable happens. One Direction, the biggest boy band on the planet, loses a member. Zayn Malik quits the band, and the internet explodes with feels. I read tweets as these girls describe the physical pain of this loss, how they can't eat or sleep or walk. I read them describe how much Zayn had meant to them. And I watch videos of 10-year-old girls crying. But, like, really crying. And then I watch as people repost these videos but with new titles that contain words like "crazy" and "creepy" and "insane." And suddenly, my YouTube sidebar contains "Compilation: Fans react to Zayn leaving. Psycho alert!" Then I watch as mainstream news outlets cover the story. I read them describe these "young banshees." I read one journalist say, "It's a commonly known fact since the age of the Beatles that there is nothing scarier in this world than a group of excited teenage girls." (Laughter) And then I ask myself a question I've never considered in my life. Why is it that the image of young girls screaming their lungs out with excitement for a pop star is considered crazy, psycho, scary, a bit much? But the image of young boys screaming their lungs out for a footballer is perfectly normal? Boys crying at the footie, that's the love of the game. Girls crying at a Justin Bieber concert? That's pathetic. And as soon as I realized this double standard, I realized that all of my curiosity about fangirls had been sparked by exactly the same judgments. I, too, had suspected that they were a bit crazy. I'd looked at images of girls screaming for the Beatles, the Backstreet Boys, One Direction, and the word that had come to mind was not "excitement" but "hysteria." And what I did not know was the history of that word. That in the 19th century, hysteria was considered to be a legitimate female mental disorder that could be diagnosed by doctors if women displayed excessive emotion or difficult behavior. The word "hysterical" comes from the Latin word "hystericus," meaning "of the womb," because it was thought that this condition was caused by a dysfunction of the uterus. And so, a treatment for hysteria was a hysterectomy. Which is what we still call a removal of the womb. And at this point, I decide to redeclare my obsession. Because I am no longer just obsessed with fangirls. Now, I'm obsessed with the way that the world talks about fangirls and the way that the world looks at young, female enthusiasm. Because, I want to know, if girls grow up in a world where words like "crazy" and "psycho" and "hysterical" are casually used to describe female enthusiasm, then how does that shape the way that those girls get to see themselves? And if girls grow up in a world that tells them that they are designed just a bit crazier than the boys, then isn't that a little bit like telling them that they are born less capable of rationality than men, less capable of reason and unworthy of the same intellectual respect as their brothers. Separately, I become obsessed with female screams. Not in a creepy way. I'm talking about, like, those shrieks and squeals that fangirls let out at concerts. I want to know why it is that some people instinctively flinch when I merely describe the sound, like it's painful just to think about it. Then I meet Amy Hume. She's a voice coach. And she blows my mind. Because she tells me that the female voice between the ages of 11 and 13 is one of the most interesting things to study. Why? Because there's this research by Carol Gilligan that says that is the age when girls begin to perform and alter their voices. For example, adding breath for maturity, (Imitating vocal fry) or adding vocal fry for apathy. (Laughter) But tell me, according to this research, when do you reckon boys begin to perform and alter their voices? Now, I guessed 18, because "men mature later," right? Wrong. The answer was four years old. Because that is when boys learn not to cry or squeal. That those are not manly sounds. And that's when I realized that a fangirl's shriek is therefore like a superpower. (Laughter) Because it's this fearless and honest expression of pure celebration and joy, and it's a sound they have not forgotten how to make. I actually reckon that fangirls have a second superpower, because they know how to do something that most of my adult friends have no idea how to do. Fangirls know how to love something without apology or fear. My years of researching fangirls culminated in this determination to write something that celebrates and vindicates them. So I decided to make this thriller comedy musical that sounds like a Beyoncé concert meets rave meets church. I called it "Fangirls," and I designed it like a Trojan horse. So it appears to make fun of these young women, only to, like, smuggle them into your heart. (Laughter) Thanks. (Applause) At one point -- Thanks. At one point, a girl sings, "Why should I hide my feelings? Because they annoy you? Or because it isn't what the boys do?" And as a former fangirl cynic, that is the question that I want to leave you all with. Why should fangirls tone it down? Because they're crazy? Or because our definition of "reasonable" is based on what it is acceptable for men to do? What if we rethink the judgments we've been conditioned to feel when we see young women screaming their lungs out with excitement? What if we decided to rethink the words we use to describe that joy, and what if we didn't allow ourselves to diminish girls with words that undermine their intelligence, their interests and their capability? Because, according to my research, they are capable of building a shrine to Harry Styles's vomit on the side of a freeway within two hours. (Laughter) That takes some executive skills in logistics and communication. (Laughter) If that isn't "capable," I don't know what is. (Applause) I reckon, instead of judging fangirls, we can learn from them. We can all die tomorrow, so why not love things while we're still breathing? And with that, I'd like to ask you all to try something with me. Can I get you all to stand up? Stand up if you can, stand up. Alright, so here's what's going to happen. I'm going to count to three and when I finish, I'm going to ask every single one of you to let out your very best fangirl scream. (Laughter) Yeah? Here is why I am asking you to do this. Because if all five-or-so thousand of you do this and really commit, we all get our first chance to hear that sound and to decide that it is not a crazy sound. It is a hopeful sound. So shall we do this? I said, shall we do this? (Audience: Yes!) Alright. OK, I am going to cheat and I'm not going to go full volume, because I'm miked and we don't want to hear that. But it means you all have to go 110 percent. You ready? Take a deep breath with me. Think of someone you love, let's go, one, two, three. (Audience screams) (Laughter and applause) You all just sounded stunning and as sane and as intelligent and as dignified as when you walked in this room. (Laughter) Thank you. (Applause)