Beginning the day she was born, you immediately had a connection with her. Though it has wavered through the years, it has done nothing but grow stronger. She's the one you got in trouble with, the one you blamed everything on (even though it most definitely was your fault), and the one that keeps you company on a lonely Friday night. They are a blessing to your life, regardless of when they came into it. She's the person you care about the most, but passionately hate at the same time. For better or for worse, she will always be your best friend and the greatest person to come into your life.

1. She makes you a better person.

You want her to grow up to be a beautiful, respectable woman. What better way to achieve that than showing her how it's done? Sure, you might not always be a star student, but she knows you're trying.

2. She knows when you're not "fine."

This goes both ways.

3. You will always be needed.

Whether it's for advice, a listening ear, or something as simple as a ride to her friends house, you will feel motherly and protective over her; always wanting the best for her.

4. You will always have someone to share your expert advice with.

Boys, family, school... you name it. You've been there and can provide stellar advice on all topics.

5. It's impossible to stay angry at her (unfortunately).

Stealing your clothes, eating the last cookie, or tattling, you cannot stay mad at her. One minute you're seething with anger, the next you two are laughing about some sly joke one of you made.

6. You always have someone to hang out with.

From Monday to Sunday, both of you will cancel any plans to hang out with each other as soon as one of you hints that you don't have anything to do.

7. You inevitably have a designated driver.

Enough said.

8. She makes you more responsible.

You want to set the best possible example for her, so you're always sure to be the mature one in difficult situations in hopes that she will too one day.

9. You always have someone who is always going to forgive you when you pick on them.

You fight like cats and dogs, but at the end of the day you don't remember what any of your fights were about.

10. She was the guinea pig to all of your jokes and make-up tutorials when you were little...actually, she still is.

She was perfect for testing out the beauty regimens you so desperately wanted to try, just not on yourself. Not only was she willing, but she was excited to be the guinea pig.

11. You always have someone to run errands and go on Dunkin runs with you.

"Want Dunkin?"

"Duh."

12. You have two closets.

Especially if you are only a few years apart, what is hers is yours and yours is hers. Half the time, you don't even remember who the primary owner is.

13. She will never judge you for anything you've been through - the good, bad, or the ugly middle school years.

Sure, she makes fun of you for your braces and glasses and lack of make-up skills. But she would never judge you for it, or for anything else for that matter. She's the most open-minded individual when it comes to you.

14. She teaches you more life lessons than school ever did.

Learning how to be the bigger person was not an easy feat, nor was going through high school, college application process, dating, or anything else first. But it was worth being able to teach her and share your knowledge with her about everything you've done.

15. Even though you might not be as close as can be, she will always be your best friend through thick and thin.

To all of the sisters out there, thanks for being you.