It was a short comment and a friendly one, left by a stranger on an Instagram photo I posted. To the casual eye, it might even appear to be a lovely compliment.

“Congrats on the weight loss!” he wrote.

It was not a lovely compliment. And I did not regard it with a casual eye.

You, dear reader, probably already know what most wise people know: You shouldn’t comment on the appearance of a woman, at least where she can hear or see you, and you especially shouldn’t publically comment on the weight of a woman you’ve never met. Even when you know a woman quite well, you shouldn’t remark on her weight or body unless you are absolutely certain she would welcome your commentary.

A split image of the author looking glam and also natural

This guy missed those lessons.

I may be an artist, but I’m not the world’s most sensitive individual. I get a lot of comments online, on everything from a comedy video to an interview photo to my author headshot on a book jacket. Often it’s wonderful. Sometimes it’s awful. To an extent, I’m used to it. But I still get mad sometimes, or hurt. In this case, I was plain annoyed.

I decided to sit with it until I could write something that might be of use to more people in the world than just him, or just the people on my Instagram. Besides, I’m almost positive he wasn’t being malicious. He thought he was giving me a nice compliment. Perhaps he imagined I’d worked hard to lose weight, or that I’d welcome the positive reinforcement. His intent was good.

But his comment was still a problem.

Women walk around all day, every day, knowing that we are instantly judged by many of the people we pass. It is neither narcissistic nor an exaggeration to say that when a gal walks into a room, people inevitably notice what she’s wearing and how she looks. Our culture trains its inhabitants of all genders, ages, and backgrounds to care about how a woman grooms herself, dresses herself, and carries herself, as well as the structure of her face and body. And whether we realize it or not, most of us do care about this stuff, maybe more than we’d like to think.

Guess what? Your body just f*cking changes. That’s what a body does; it never stays the same.

Of course, this doesn’t mean that every single time a younger woman walks into a restaurant, every single person stops and stares. Some people go about their business, occupied with a thousand other more important things than how big the butt of the next customer may be. Do you have time to stare every single time somebody new walks into the grocery store or the coffee shop? I sure don’t. And yet I do know that if a woman walks through my field of vision, I’m way likelier to look at her body or her outfit than I am if it’s a man (unless he’s fine as hell, in which case I will stare for days). It may just happen for a moment, and there may be no internal monologue attached to it, but it happens.

In a country where our next president rose to fame in part because he takes deep pleasure in ranking young women and underage girls in the form of beauty pageants—which manage to be both boring and phenomenally creepy simultaneously—the quick and easy judgment of women is a thing. It’s a very big thing.

Would I have been annoyed if that guy on my Instagram said, “You look beautiful?” Of course not. “Great hair,” was another legit option. “Amazing dress,” is always a good move. “You are glowing,” is nice! “Your eyes sparkle with the fire of a thousand suns, my glorious queen” would’ve been weird… but still in the realm of acceptable statements. But why did he have to mention my weight like it’s any of his damn business? All I did was put up a photo of myself standing by a countertop. The countertop had some funny objects on it. He did not remark upon them.

Here’s what ran through my mind when he congratulated me on weight loss:

1.”What?”

2.”Have you been monitoring my weight, you gross stranger?”

3.”Who the f*ck are you?”

My first response was one of confusion. My second one was the result of me feeling justifiably sketched out that some guy was keeping tabs on how big my body was, and figuring out in his mind whether that was acceptable. But it’s the third response I want to highlight.

Unless she tells you, you never, ever, ever know why a woman’s body changes in size. You just don’t. And you should never, ever, ever assume. Just because a woman loses weight does not mean she is healthy or happy. And just because a woman gains weight does not mean she is unhealthy or unhappy.

I’ve known women who lost weight for a lot of reasons: healthy exercise with the assistance of a helpful trainer or guide; training in preparation for an athletic goal (this can also entail weight gain because, surprise, muscle ain’t weightless); fad diets that worked for a minute before the weight inevitably returned; frightening exercise addiction that resulted in injury and even hospitalization; pill addiction; various eating disorders; other illnesses from the flu to cancer and beyond; pregnancy loss; changed eating choices under a smart, encouraging expert’s supervision; changed eating choices under the “guidance” of monsters and charlatans; stress; trauma; grief; lack of sleep; abuse; income loss… the list goes on.

And sometimes, guess what? Your body just f*cking changes. That’s what a body does; it never stays the same. Being human is complex, and it ends the same way for us all. Along the way, bodies grow, expand, contract, thrive, decay, and crumble.

The next time you feel the urge to tell a stranger something about her weight, bite your tongue.

When I took that photo, I’d recently lost five pounds due to illness. I’d had bronchitis for six weeks, a period that would eventually stretch to 11 weeks before I started to feel anything close to 100 percent better.It was hard for me to speak for an extended period of time, which was a real problem since some of my income is from acting and from speaking at colleges. It was hard for me to focus, which was a real problem since the majority of my income is from writing books, screenplays, essays, and articles. I hadn’t made any effort to lose weight. In fact, I felt like sh*t.

I looked good in that photo. Pale from illness, but good. In part it was because I’d mustered up the energy that day to do my hair and makeup. I have my less comely days, but I think I often look good. Thanks to my upbringing and my work in therapy and elsewhere, I walk around with the confidence that I have the right to exist, and that I have something worthwhile to offer the world. I’m not skinny, but skinny doesn’t mean pretty, and fat doesn’t mean ugly, and “average” doesn’t mean average. I’m sexy and smart and hardworking, and often fun to be around. I do my best to treat folks with respect when I believe they deserve it. I believe most folks deserve it.

In my adult life, I’ve weighed as little as 50 pounds less than I do now and as much as 10 pounds more than I do now. I’ve had fun at every weight. I’ve had low blood pressure at every weight (thanks, Dad!). I’ve been happy at every weight. And I’ve been depressed and anxious at every weight (no thanks, entire family’s genetic history!) At my lowest weight, I was suicidal. People told me I looked good then too.

The guy who made the comment is likely not a bad guy. In all likelihood, he’s a very good guy. He was just doing what he’s been trained to do: applaud a woman who loses weight and (to her face or behind her back or simply in his own mind) ignore or criticize a woman who gains weight. He’s running the same tired old program a lot of us received when we were born into this particular culture.

I hope he sees this. I hope he learns. But if not, I have a feeling somebody else will. And what I’m asking you, handsome, beautiful, and/or sexy reader, is pretty simple: The next time you feel the urge to tell a stranger something about her weight, bite your tongue. Tell her you like something she wrote, or said, or did. Women don’t hear enough compliments about what we do. And we do so very much in a day, especially when we’re not busy wasting time worrying about the number on the scale. So encourage us not to worry. Encourage us to do good work and to be good people. Validate that. It means a hell of a lot more than you might think.

Sara Benincasa is an author and comedian. She’s @sarajbenincasa on Twitter. Her weekly zine is The Stories.