I went to high school with a girl who talked a lot about her interest in Hitler. Most of my friends thought it was weird; when she started talking about the Third Reich, we would try to change the subject. It wasn’t until I saw her reading Mein Kampf that I understood that it was not interest she felt, but admiration.

As a Jew and granddaughter of a Holocaust survivor, the situation made me uncomfortable. I remember feeling awkward and upset whenever she mentioned Hitler or made anti-Semitic jokes. But one of her best friends was Jewish, so it seemed impossible that she actually felt hatred towards Jews. I was fifteen and scared to draw attention to myself. I didn’t know what to do. Then she suddenly announced that she was moving away, and that was that.

I’ve thought of her occasionally since then, wondering what she’s doing these days. Then the white supremacist march in Charlottesville happened. I looked at the photographs from that day and realized that I wouldn’t be surprised to see her in that terrifying crowd, holding a torch, mouth open in a scream.

Because white supremacists seem like monsters to me, I forget that they are real people who could be sitting next to me in math class. I understand that the United States has been built on white supremacy from its beginnings, but it’s emotionally difficult for me to wrap my head around how individuals can be so hateful. I keep clicking through photo after photo of the awful mob in Charlottesville wondering who allowed these people to become that way.

I realize now that it’s people like me — people who let jokes slide because the person who’s saying the hateful things doesn’t seem like a monster. It’s easier to ignore those everyday moments than to be the person who says, “That’s not OK.” It never seemed like the girl reading Mein Kampf in my drama class would actually support white supremacists or would march alongside them. I thought that if I said anything, it would look like an overreaction.

On Aug. 12, James Alex Fields Jr. went to Charlottesville and drove his car into a crowd of counter-protesters, killing Heather Heyer and injuring at least 19 others. For the past year, he’d been living in Maumee, Ohio — about an hour and a half away from Oberlin. He graduated high school in 2015, just as my classmate and I did.

Fields’ history teacher recently said that his student had idolized Hitler to the point that it worried his classmates. But one of Fields’ peers said that he wasn’t a scary outcast — he had friends. He was a “normal dude” who sometimes made weird jokes, including ones about the Holocaust. Sounds familiar to me. All the uneasiness others felt about Fields’ behavior never transformed into preventative action. No one ever stepped in to halt the process that culminated in a car plowing through a crowd, ending Heather Heyer’s life.

People like me — well-intentioned people — let violence happen when we don’t speak up. My classmate wasn’t harmless, though as far as I know, she has never marched in a white supremacist rally or physically hurt anyone. Last November, she voted for Donald Trump.

Don’t excuse people like her when they make racist, anti-Semitic, or anti-Muslim comments. Fields spread hatred for years before he drove to Charlottesville. Someone could have — should have — stopped him. If you don’t know how to do that, find a friend who feels the same way and tackle it together, or ask someone you trust for advice. Don’t let people who tell hateful jokes off the hook. Because white supremacists aren’t hidden monsters. They’re people we know.