1. You know how unconditionally loyal she is and always has been.

2. You know she loved you even when you went through that phase in your tween-teenage years that turned you into an angsty bully.

3. When your friends become best friends with her, you know she’s well taken care of.

4. Nothing will ever compare to how much fun you both had while playing Barbie dream house with your new Barbie camper that you got for Hanukkah back in 2007.

5. You know it’s you two against the world.

6. You know she’s been there for you through everything.

7. She will always vouch for you no matter what the situation is.

8. You know she is the only person who understands how insane your family actually is.

9. She’s obligated to favorite all of your tweets, like your Instagram pictures, and do the same for all of your friends.

10. You learn that you have to share everything. In my case, a Jack and Jill bathroom. Although I would take that over the communal ones in my college dorm any day.

11. You know she has looked up to you since day one when you both had matching t-shirts, one that said “Big Sis” and one that said “Little Sis.”

12. If your sister plays a sport, you know the feeling when you see her name in the newspaper after a rival game. You think your sister is perfect and strong and you are so proud to yell, “THAT’S MY SISTER!!!” from the stands when she scores the winning goal.

13. If you’re anything like me, you let yourself fall for people way too easily. It’s impossible to count the times my sister has let me cry my eyes out to her about my latest heartbreak or listen to me rant about what he did to make me so upset.

14. You know that your sister is your unconditional best friend.

15. You know that seeing your sister grow into such a diligent, smart, kind woman has been the light of your life.

16. My sister has taught me a million things and I hope I’ve taught her a billion more. You meet a lot of temporary people in your life, but your sister is forever. There are an infinite amount of things you know about your sister and so much more to thank her for.