Dear Seventeen:I don't feel as smart as my classmates, even though my best friend and my family say I'm smart. How do I improve others' opinions, and my own, about how smart I am? — Audrey, 16, Fort Worth, Texas

Dear Audrey: Of course you're smart. Just the fact that you took the time to write to us about wanting to make things better in your life shows how smart you are. And the truth is that everyone is smart in her own way: Some people don't do great on tests or with schoolwork, but they have great common sense. Some people may not know random facts, but they're emotionally smart — they're sensitive, kind and caring.

So whenever you start comparing yourself unfavorably to your classmates, stop and say, "I am smart." Then make a list, either in your journal or in your mind, of all your strengths. That way, you'll replace your habit of thinking you're not smart with the habit of thinking you are smart.

The more often you do this exercise, the more confident you'll feel! (But, Audrey, if you're struggling in school in any way, talk to your teachers about what you can do to improve.) And remember, while your classes may feel really grade-focused, the most important part of school isn't your GPA. It's what you learn: about your subjects, about the world, about other people and about yourself.

Continue to seek answers, like you have by writing to us, and your wisdom will continue to grow.

Dear Seventeen: My sister, who's my best friend, is leaving for college in the fall, and I won't be able to visit her. How do I learn to live without her every day? — Maureen, 15, Baltimore

Dear Maureen: You're so lucky to have a sister you consider your BFF. It will be hard for you to be apart, but you clearly have the kind of bond that will keep you emotionally close.

To make sure you stay up to date on each other's lives, rely on your phones and computers! Get calling and texting plans that will let you talk however long you'd like or text as much as you want at no additional cost. Set up an IM or chat program, and send each other pictures often. And before your sister leaves for school, agree to set up a "meeting" over the phone at the same time every week. Having a set time will give you both something to look forward to, and it will help make sure you don't let other things get in the way of your bond.

It shouldn't be difficult for you two to stay close, but also remember that this is a time for growth and new experiences in your sister's life. It's important for her to learn independence.

There may be times when she can't be there for you right away, but that doesn't mean she loves you any less. It just means that she is becoming her own person, which is something we all need to do.

If you support your sister's new life, you and she will grow together, and your relationship will become even deeper.

— Questions may be sent directly to Seventeen magazine at: dearseventeen@hearst.com. Distributed by King Features Syndicate.