The other night I had dinner with my youngest brother. It was a nice, mellow evening, and I stopped by Insomnia Cookies on my way home to get up some decadent, warm chocolate cookies to share with my roommate.

On the train clutching my box of cookies, I was bothering no one and reading my book when a woman tapped me on the shoulder.

When I looked up, she said: "You're so lucky, just eating whatever you want and not caring. I'm a dancer so I can't do that."

After the initial sting of being fat-shamed in a public space by a stranger wore off, a slew of thoughts about a rebuttal ran through my mind.

Do I tell her that I first knew I was fat when I was 7 years old?

Do I tell her I saw my first nutritionist, started counting calories and working out at the gym when I was 12?

Do I tell her that, even on my good days, I don't look in the mirror and automatically like what I see there?

Do I tell her that every day is a battle to love myself?

Do I tell her that I'm still half convinced the last guy I dated didn't want me in the end because I was too fat?

Do I tell her that the fact I am on a subway carrying a box of cookies is one of the bravest things I've ever done?

Do I tell her that she has just made one of my biggest nightmares come true?

Do I get snotty and say I can tell that she doesn't eat much because of her wrinkled skin?

I am professionally glib. I'm a writer. I'm witty all day, or at least, I try to be. But it was after 10:00 pm and I was hot and tired.

So instead I just said "eff you" and left it at that.

Then, I shared this story on Facebook.

I was touched but not surprised when so many of my friends reached out to express their indignation.

I almost didn't share the story at all, because I didn't want to appear like I was fishing for what people view as compliments.

"You aren't fat. No!"

I wasn't looking for false reassurance, I was looking for a place to share my anger.

It's taken a long time for me to get this angry about the way myself and other fat people are treated on a daily basis.;

I've spent most of life slouching apologetically along.

I feel guilty and bad when my hips have to squeeze past the cup holders in movie theaters. I feel embarrassed about the swell of my stomach when I take up the middle seat on the subway.

My cursing at a stranger was exceptional, because instead of blushing or saying something nice and pleasing I lashed out.

And I don't regret it.

It doesn't matter that we were in a relatively public space.

No matter the reason, no matter your intentions, it is never acceptable to enter someone else's space and talk about what they are eating, or how you perceive their relationship with food (and by extension, their body).

A former coworker, a writer and reporter I like and respect (we share a passion for cats and she helped me through a tough breakup) commented on my post.

She prefaced her comment by saying, "I know I'm going to get reamed for this but ..."

So needless to say, I was already braced for impact.

On the surface her remarks were kind, and they were remarks I've heard before.

She didn't think of me as fat. She thought of me as beautiful and confident. Maybe the woman was just making small talk. Maybe I projected the way in which I saw the world and my own insecurities onto this innocent woman.

"I'm skinny," she said, "and I never think about my weight when I talk to people about food."

I felt immediately ashamed.

I started to replay the encounter on the subway in my mind. Was she right? Was it me and not this poor stranger who was in the wrong?

Then I started thinking about the privilege involved.

The answer to my questions was in my friend's comment already.

I'm a fat person, she is a thin person, and so her relationship to the world is different than my relationship with the world.

Privilege — thin privilege or any other kind of privilege — doesn't mean you aren't entitled to having an opinion.

It simply means that you have to stop, acknowledge that your life, circumstances and experience make it practically impossible for you to understand where someone else is coming from.

Of course if you are thin you don't think twice about talking to someone about what you are or aren't eating. Being thin gives you that right.

But as a fat person, there are things I just can't do without worrying about them that most skinny people can do if they want to.

I can't just eat while walking down the street.

I can't just order dessert.

I have to figure out if eating on the go is worth being harassed on the street, a thing that happens — and often.

I have to decide if eating dessert is worth the well-meaning comments from skinny friends about how they aren't eating carbs right now. They don't mean with it malice, they just don't think about it.

Because they don't have to.

Like it or not, most people today view weight as being a choice.

"Eat right and exercise and you won't be fat," is the common thinking.

I work out, I eat mindfully, and I'm going to remain at a stolid 210 pounds.

I'm strong, I'm fast an I'm healthy, but because I am significantly overweight, I do not have the same basic rights to putter around existing that naturally thin people have.

It doesn't matter what weight I am. It doesn't matter what weight you are. What matters is how we treat each other.

If I was eating with a skinny friend and she opted not to have dessert I would never tell her that she needs to put some meat on her bones. It goes both ways.

Her body is her business. My body is mine.

Let's remove shame from the equation if we can. I'm not saying we should all start cursing a blue streak at people who body shame us, but maybe let's use some of that righteous indignation for good.

Let's stop apologizing for our bodies and start defending them.

Rebecca Jane Stokes is an editor for Newsweek living in Brooklyn, New York. Follow her on Twitter for more of her work and insights.

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An earlier version of this article was originally published September 2016 and has been updated.