Dear "Former" Self:
The unfortunate thing about this letter is that you won't get a chance to read it. However, that does not defeat the purpose of this, my "Present" Self, composing it.
I know school is a pain in the ass. All subjects like Math and math-related Sciences seem to do is bring your overall grade down. And I know you look at your friends who can perform just as well in those subjects as the liberal arts and ask why you can't do that, too. Well, I don't have an answer to that question, but I can tell you that your seeming "deficiency" in those subjects didn't hold you back in the long run. Even when you got older, you still wished you could work out an equation with some reasonable assurance that it was somewhat right, but other than the GRE exam, you won't need to see those odd symbols, parabolas, sines and cosines again. Your staying up late nights doing all of your homework, reading and studying for those AP exams will pay off--in the long run you will be able to do what you can only imagine "in theory" right now: you will be able to go to the school that you choose as the best option for you, if not quite for what you expect at first.
There will never be a time when your parents aren't looking over your shoulder. What you will learn is that it is better to make it easier for them to do that. They'll never admit to you that they were more strict with you than with your siblings, no matter what you do, so just keep that knowledge to yourself. It won't get better, either--you'll see what your siblings will be able to get away with, things you would have been grounded for ages for, and you'll immediately feel the injustice of that. You'll hide that well, though. The only thing I can say is that as you get older, you realize that your parents are human, too. They made mistakes and they had to learn how to be "parents" just like you learn how to do anything else in this life. You will have to admit, though, that their strict upbringing impressed upon you the ability to choose well between right and wrong. Had they been more lax, well, you probably wouldn't have turned out as well.
Your parents will never like any of the guys you bring home--you may as well know that right now. It's true, some of your choices won't be very good, but it is impossible not to throw into the mix the fact that you are the oldest and that it is harder for them to part with you in some ways, especially your father. However, on the other hand, they will always be accepting of your friends, no matter who they are. You are going to realize that you tend to stay in relationships too long, especially when you feel like you don't have any other dating options waiting for you if you were to end what you are a part of. As you move from place to place, school to school, and job to job, your experiences will impress upon you that there are two classifications of things in life: things that are meant to stay with you and things that aren't meant to last. Once you learn this, you will be more and more able to distinguish between them. You will go through a process where you will have to do what you know inside of you that you need to do--you need to go it alone to be able to learn what "you" is. When that happens, it won't matter if you're on your own or not anymore. And, it won't be as scarey as you think. In the end, you will be content with your own company and more comfortable with yourself. Both of these results will help you build better, longer-standing and more stable relationships of all kinds in the future.
Secrets you'll have to admit to yourself:
You're a romantic. Just live with it.
You can throw a ball as well as any guy--don't let them tell you otherwise.
You'll always be a "big sister" no matter where you are or how old your siblings get.
The Indigo Girls will save your life more than once.
Relationships aren't always what you think they are, and love is going to defy conventions for you.
You'll always want to do dozens of things with your life. Narrowing that down is not necessarily a good thing.
Above all, relax. When you do that, you will invite more people to you. You're going to have to learn openness, and thankfully you will, but not without a lot of help. That means not shutting anyone out who has something to offer--and that means everyone.
Until your "Future" self comes along,
Your "Present" Self