As I began typing this letter to you, I turned my music on without even noticing what would come on when I pressed play. That's when L.A. Baby, by The Jonas Brothers began blasting through the speakers of my computer, and all I could think about was dancing to this song in my living room in the summer, and screaming it at the top of our lungs while we were tubing on the lake.

You've been there for it all. You've been my best friend for as long as I can remember, and at this point, I can't even picture my life without you in it. I wouldn't even consider you my best friend, I consider you my family. I consider you my sister.

Relationships like the one we have come once in a lifetime. They are so rare and I think we fail to acknowledge just how lucky we are to have each other. There isn't anyone in the world I can talk to the way you and I do, and I am so thankful that I have you.

It's so comforting knowing that if I'm having a bad day or if I'm feeling low, you'll always be a phone call away. I am also thankful for the ridiculous pictures from our childhood you send me on random occasions. They always make my day, and I don't think you understand how frequently I look at them. I loved growing up with you... I still do (we aren't done yet, even though we technically are legal adults).

As I sit here trying to understand how we got so old so quickly, I can't help but think of all our amazing moments along the way (to name a few): when Tyler and Nico stole the conch at the lake, our insane home videos, Camp D'Anna, night swimming, "only on Tuesdays", Harlem Shake in Aspen Dental, Duck North Carolina, Captiva Island, you choking on smiley face french fries, taking the quiz at the end of "A Cinderella Story "and always getting Sam because we knew the answers by heart, your 101 dalmatians computer game, the Mary E. Griswold School song, when we got Hillary Duff concert tickets and I thought they were movie tickets, getting snowed in a Mohegan Sun, when you met Nick Jonas before me and I got psycho jealous, NYC trips, Newton Street, and so much more. The list is so long that by the time I finished writing it we'd be nearing your 30th birthday.

I really hope you understand how much I love you and just how much all these memories mean to me. Without you, I would not be the person I am today.

On your 17th birthday, I wrote to you: "I seriously can't believe how old we're both getting. It feels like yesterday we were playing together on Newton Street. Time really does fly. So, what I really want you to know is that I'm so thankful I have you in my life. You're my partner in crime... and I promise that no matter how far apart, old, mad, or busy we are, we will always be sisters". I still hold that promise to this day on your 20th birthday. I will still feel this way on your 40th birthday, 60th birthday, and even your 100th birthday. I will love you for as long as I live, and I will never stop causing trouble with you.

So happy 20th birthday to my big sister. Thank you for always being there for me, listening to me, and supporting me no matter what. I can't wait to see what the future has in store for us.

The Dam girls are going to conquer the world. Get ready.