* All those times you were sure that big fun was going on and you weren't part of it - just sit back and enjoy the quiet. The quiet will end, the ginormous fun is coming - in the form of silliness and ridiculousness involving dancing, dump trucks and Grover the likes of which you can't imagine.
* Stop worrying about your social life, and friends. You already know two of your best friends, they happen to be your parents, and live with two of the best people in the world. You're going to meet three other spectacular people and share your life with them, with never a dull moment.
* There will be a time when you get such little sleep you feel sick, and look worse and aren't even able to recognize that you are tired. Enjoy it while it lasts!!
As I think about you today, and how you evolved into this life I lead now, I just had to sit back and smile. For as different as life has become, it's still very similar. You used to push yourself hard until you drop. You now are involved in a marathon of a different kind involving pushing through while exhausted. I loved your life at 20, but I have to tell you that life in your 30's far exceeds and I'm pretty sure life in your 40's with this crew you have acquired will be even better.
Your 30 something old self