Everyone will turn against you.

 Don't waste those 3 years loving someone who in incapable of loving you back. You find the man of your dreams later in junior year anyway. (P.S. He becomes your gay best friend in the end)

 Your life won't be easy, you'll have to handle lots of problems that many teenagers usually don't have, you might have to leave some projects but it's going make you a great winner, someday...

 Don't believew him when he tells you that he's going to leave his wife for you. You will waste five years of your life waiting.

 You're going to discover that the most rewarding part of your education was the time you spent away from school. Don't let it define who you are; nobody else judges you by that standard.

 Yes, I got your letter from the time capsule. Do not be so excited about that trip to the theme park. You don't go on any rides that day. Thankfully, you will eventually. Smile more. Things are not nearly as bad as you might think they are.

 don'y ever go near razor blades. you'll regret it when you have scars running up and down your body.

 You get the man of your dreams. Glad you didn't go out with the morons that liked you. . . saves you from telling a lot of awkward stories.