1. Every time you tell a story about one of your favorite memories, her name is in it.
The time we mixed orange juice and milk together to see if it would really make us throw up and it totally did is somehow a really good memory because we did it together.
2. You can be your ~*weirdest*~ self around her.
Rolling around the living room covered in whipped cream singing Adele songs even though you know this is going to make a mess would not be acceptable with anyone else.
3. You can throw random movie quotes at her and she gets every single one.
Totally out of context reference to a 1989 movie about witches we watched when we were little? I didn't even have to say the whole line and she knew.
4. No matter what you do, she'd never think of judging you.
All of the heartbreaks, that time I got a speeding ticket because I was listening to Gwen Stefani way too loudly, she knows all of them, which means she was way more understanding when I dated someone who was a pile of garbage because it was really hard to tell he was a pile of garbage because he had really nice glasses and sometimes that confuses me.
5. When something good happens to you, no one's happier for you than she is.
Even if everyone else is jealous and acting like dicks, she's throwing me a party full of balloons. Like, there aren't even any people there. It's just a room full of balloons. Full of glitter.
6. She's known you since one of you was a fetus.
This in and of itself is pretty hard to top, so she wins by default.
7. Your inside jokes are epic and span your entire lifetime.
I can say, "Well, they did fog," out of nowhere and we will both laugh for 45 minutes and then for another 45 when she says it too.
8. She knows all the songs you secretly like and she~* LoVeS*~ them too.
So the second we get in the car, it's Ashlee Simpson's "Pieces of Me" on fucking blast. Yes, I love that song.
9. You can immediately tell when she's having a bad day.
Even if you're just texting each other. You would've normally put a party hat emoji after the word "party" what is wrong are you okay?!
10. She'll always try to talk you out doing something dumb, even though that never works.
Because sometimes I need to be able to text my exes photos of angry-looking farm animals at 3 a.m. as part of the Healing Process and this habit cannot be stopped.
11. She pushes you out of your comfort zone.
But I don't want to leave my house and put on pants, even if it involves drinkiiiiing. Fiiiine, I'll go. Oh, hey, this is fun!
12. She's been there through every single breakup ever and she remembers all of them.
She knows every single guy by name, so much so that when I'm dating someone who is basically Miguel from high school, she's like, "Please, this is so 'Miguel from high school.'"
13. She doesn't care how many times you've both seen Clueless.
She'll still watch it with you. Because it never gets old.
14. Her closet is your closet.
Even if we have different bodies, we've both inherited so many clothing items from each other it's tough to tell where one closet ends and the other begins.
15. She is basically like your own personal shopping police.
Thank you for telling me I do not need another white shirt with black stripes because you know for a fact I have 74 of them hanging in my closet right now. See? This is why we work.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.