1. You immediately call her when you see something really funny happen in your daily life, and know that only she will appreciate the level of crazy that was the guy standing in front of you at the post office.
2. Even though neither of you is particularly a fashion maven, you both trust each other implicitly when it comes to giving good style tips and making sure the other one always looks her best. She will never steer you wrong.
3. You can’t even really remember how the two of you became friends, it just kind of started happening and snowballing down a giant hill of love and going out together, and never really went through that weird phase where you weren’t sure how close you wre.
4. You have a mutual favorite movie or show that the two of you can quote down to the last line. Everyone has learned to hate your conversations that exist only between the two of you and are entirely comprised of quotes from said movie. It has basically become your second language.
5. Speaking of which, you completely have made up terms for people and very specific things.
6. If you were in a bind financially, you know that you could go to her for a little help (if she could provide it) or advice with no judgment.
7. The biggest part of one of the two of you having a new significant other is the whole “Introduction to my Soul Sister” part where you are basically expected to be a more harsh version of Simon Cowell and put the date through the judgy tests which prove his or her worthiness for the crown.
8. Once this new SO has acquired your approval, they know that they are in this for the long haul.
9. Pretty much everything she has ever recommended to you in terms of entertainment has been a spot-on choice. Even though you have different tastes in music or art or movies, you know what the other one likes well enough to see something and think, “This is definitely for her.”
10. The two of you have been to at least one concert together, and it was amazing.
11. You can always go back through your chat histories, text messages, and email exchanges to get a quick laugh or some reassurance that you are loved and understood by someone — that you have family who you aren’t even related to.
12. Sometimes you rediscover old inside jokes that the two of you used to have and remember how hilarious and ridiculous they were all over again.
13. Whenever you are really reeling from a new breakup, you know that you can always go to her to remember that life isn’t so bad, and your ex was definitely a dick who did not deserve you. (More deep reflection can come later, when you aren’t just getting wine drunk and watching shitty movies to take your mind off of things.)
14. She knows things that you have told literally no one else in the world.
15. All of your secrets are safe with her, even if the two of you get into a little fight that means you aren’t speaking for a few days. The little problems in day-to-day friendship do not affect the amount of trust and loyalty you have for each other overall.
16. Every time you talk about her to someone who doesn’t know her yet, you gush a little bit.
17. You help each other practice for job interviews, and are almost as nervous/excited about the other one getting hired as you are about your own job opportunities. (And you know that she is more qualified than anyone for the position, no matter what it is, of course.)
18. The two of you pig out together and never worry about the other one judging your eating choices.
19. Your friendship makes you feel, in a lot of ways, much less scared about the future and the problems which might lie ahead of you. Whether it’s bad relationships, a tough career, financial troubles, or just general life disasters, she is something of a security blanket for you. You have the privilege of knowing that there is more than one kind of love to carry you through, and you are well-equipped with a lot of it. 
