1. Tanning is stupid.
2. Wear sunscreen and sunglasses.
3. You're not a prude; s/he is a jerk.
4. It's not "a hang-up"; it's known as "natural modesty."
5. Christian doctrine is right on all that sex stuff. It can seem like SUCH a drag, but it turns out to be true. Make sure you know what it really is (hint: not necessarily what The New York Times says it is), and remember that God loves you, no matter who you are.
6. Truth is what is.
7. You don't have to finish a drink just because someone (including you) bought it for you.
8. Sunscreen: wear it.
9. Smoking: extremely dumb and gives you premature wrinkles.
10. It's harder to learn stuff as you age, so study and learn languages NOW.
11. Even though one distant day you'll be too old to have babies, you'll never be too old to fall in love and get married.
12. Sunscreen. I'm serious. Thirty-somethings don't envy you your emotional turmoil, but we do envy you your beautiful skin. Sigh.