Don't reject trying new things because they are popular.

 Stop eating boogers.

 Sallie Mae is an evil bitch. If you hear that name RUN!

 Don't cut yourself, you are worth so much more than you think you are. Also, stop being such a jerk to everyone who tries to help you. And take your meds.

 Don't be afraid to pursue your dreams just because they are fanciful and your parents will disapprove.

  Don't let your grief define you. Don't use it as a crutch to avoid dealing with the tough parts of life.

 Don't go out with her, she's a psycho who will eat 3 years of your life.

 You won't be funny looking forever. You're going to start going to the gym, putting on muscle, you'll lose the belly and the chubby cheeks. Contact lenses will open up your face. Girls are going to start to notice you. Don't worry, you're not going to be a virgin forever.