There’s the theory: The positive representation of minority groups in media is important to give people of different backgrounds and identities potential role models. But while this sounds nice in theory, it can be difficult to wrap your head around what, exactly, this means — why these fictional role models matter so much in the first place.

On Twitter, Mary Swangin, who works at a comic book store in Indiana known as DCBS, gave a concrete example of why this kind of representation matters so much for LGBTQ people. In a series of tweets, she told the story of a recent shaken-up customer who was able to come to terms with her sexuality through the TV show Supergirl, in which a major character came out as gay:

So, I want to tell you all what happened in the store today. It's probably the single greatest moment I have ever experienced working here. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek After the usual Saturday rush, a teenage girl comes in. She looks absolutely terrified and when I greet her she jumped. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek She starts going up and down the new release wall and the poor thing looks completely overwhelmed. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek So, I make my way over to her and ask if I can help her find anything. She quietly admits that she was looking for Supergirl. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek We're walking to the Super area when I ask if she watches the show. She smiles a bit and nods. Says Alex is her favorite. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I mention that I'm a huge #Sanvers shipper and the poor thing just breaks down in tears. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I'm trying to figure out what the hell I did to upset her. She's crying and I'm freaking out. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek After a minute or so, everything clicks. I'm staring down a crying baby gay. One who was having some big issues. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I tell her that it was hard for me when I wanted to come out too. She finally stops crying and asks me if it gets easier. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek We sit at the coffee bar and talked for a while. She tells me that after seeing it all over Tumblr she binged SG. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek And when she got to Alex's coming out arc was when things hit her. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek She tells me that she's just wanted to kill herself for so long and that she had tried but just made herself sick. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek But as Alex's arc continued she said she realized that she started to see that she could be happy, that she could be loved. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek She didn't want to die anymore. For the first time, she didn't want to die because she got to see Alex be amazing and be queer. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek She said she came to the store hoping to find something to get her through the hiatus, so she wouldn't fall back in depression. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek She had no idea gay comic characters were a thing, but wanted to try. I tell her about Batwoman, Midnighter, and Renee Montoya. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I pull out my starters which are Batwoman: Elegy, Midnighter, and Gotham Central. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I also dug up a copy of the Adventures of Supergirl, just to get her through. Lol. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek She had enough cash for one and was torn on which to get. She decides on Batwoman and asks if I can hold the rest for a while. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I was having an internal crisis at that time, because this kid was me years ago. I was barely holding off my own tears. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek I ended up buying the other 3 for her and I make her promise me that in 10 years she'll help another queer kid. — Mary (@sapphicgeek) December 3, 2016

@sapphicgeek So, I'm out 60 bucks and I cried in the bathroom for an hour but it was damn worth it. — Mary (@sapphicgeek) December 3, 2016

This example is particularly touching, but it’s also representative of a bigger shift that media has helped push through over the past few decades. With shows like Ellen, Will and Grace, Queer as Folk, and Six Feet Under, there were more and more media examples of gay folks just being human that helped show the rest of America that this isn’t a group of people you have to fear or treat unfairly in social situations or through the law.

LGBTQ groups argue this is one reason they were able to build support for same-sex marriage so quickly over the past few years (from 27 percent in 1996 to 60 percent in 2015), as individuals coming out and better media representations showed Americans that LGBTQ people are normal people trying to live their lives just like anyone else.

As a gay man, I went through something similar. I always knew that my parents were accepting of gay rights, and that they would love me no matter what. But knowing that is frequently not enough — the mind is very good, especially in your teen years, at getting you to doubt yourself and your place in the world at every turn. So when I saw my parents watching Will and Grace for the first time and laughing with the characters, it gave my sense of my parents’ acceptance a concrete example.

I wouldn’t come out for a few years. But when I did, I can genuinely thank a show like Will and Grace for making it easier. It became less about waiting until my parents were ready and more about waiting until I was ready.

And I had the privilege of knowing my parents accepted me all along. In a situation like the girl who visited the comic book store where Swangin works, it doesn’t seem like it was that easy. In those cases, when a person has no one around her accepting who she is, it’s even more important that she can turn on the television and see that, at the very least, someone out there in the world will accept and love her no matter what.

Watch: The march of marriage equality