Ms. Rowling’s association with Ms. Forstater doesn’t come as a complete surprise; in June the author was criticized for liking a tweet by an anti-trans YouTuber, which her publicity team tried to pass off as a “clumsy and middle-aged moment.” But this week was the first time she explicitly broadcast her viewpoint to her 14 million Twitter followers.

As a devoted Harry Potter fan who also happens to be transgender, it was like a punch in the gut.

For the past decade, I’ve been an active player in the Harry Potter fan community, serving as the spokesperson for an independent nonprofit inspired by the boy wizard, sitting on the brain trust for a prominent Harry Potter fan conference and making videos about the impact the series has had on my life. I’ve seen the mind-blowing creativity of fans — from wizard rock music to cosplay to fan fiction that will make you weep — as well as their unparalleled capacity for positive change. Fans have organized in Harry’s name to donate over 400,000 books around the world, campaign in support of marriage equality and even convince Warner Bros. to switch to ethical sourcing for its Harry Potter-branded chocolates.

It was this community of loving, passionate people who accepted me with open arms when I came out as transgender at the age of 25. While I was nervous about coming out to some relatives and acquaintances, I never doubted that the Harry Potter fan community would accept me for who I was. After all, we all adhered to the values we learned from the books about being yourself, loving those who are different from you and sticking up for the underdog.

The book series, which I started reading shortly after its debut in the United States when I was 9 years old, was an escape from my lonely childhood of gender confusion. I used to dream about characters from the books showing up on my doorstep to whisk me away to the wizarding world, as they do for Harry in the first book. As I grew up and the series continued, I learned about the importance of critical thinking and standing up for your beliefs — as when Harry has to fight back against a government-sanctioned disinformation campaign denying the return of the evil wizard Lord Voldemort.

I internalized the half-giant Hagrid’s stance on self-acceptance in “The Goblet of Fire”: “I am what I am, an’ I’m not ashamed.” I felt Harry’s grief for his classmate Cedric and godfather Sirius after the deaths of my own classmates and relatives. I saw parallels between the politics of a war-torn wizarding world and the post-9/11 landscape unfolding around me.