This thread takes effort.

Enjoy the power and beauty of your youth. - I think I did.
Don't worry about the future. - How do you prepare for it without worrying?
Do one thing every day that scares you. - No. Screw you.
Sing. - I do. But people tell me to stop. xD
Don't be reckless with other people's hearts. - I don't think I have been.
Don't put up with people who are reckless with yours. - I don't.
Floss. - Hell yes floss.
Don't waste your time on jealousy. - When you've been with the same person over a decade, a little jealousy can be flattering. Don't be serious about it though.
Remember compliments you receive. - I'm sure that if I receive any I will. Bawwww
Forget the insults. - Working on it. xD
Keep your old love letters. - I have one in my wallet. It says "You have nice boobs."
Throw away your old bank statements. - I don't think BJ would go for that. He's all about keeping records.
Stretch. - Every day.
Don't feel guilty if you don't know what you want to do with your life. - But I do know.
Get plenty of calcium. - I just got a prescription with a lot of calcium.
Be kind to your knees. - I try. ;_;
Whatever you do, don't congratulate yourself too much, or berate yourself either. - I don't know about this one.
Enjoy your body. - Oh hohoho, I'll get right on that.
Use it every way you can. - Screw that one.
Don't be afraid of it or of what other people think of it. - I'm starting to get the feeling this guy's trying to con me into anal.
Dance, even if you have nowhere to do it but your living room. - Sometimes you gotta dance it out, bitch.
Read the directions, even if you don't follow them. - No.
Do not read beauty magazines. - I don't. I got free subscriptions to American Baby and Woman's Day though. xD
Get to know your parents. - I know them more than enough.
Be nice to your siblings. - Sometimes this takes an unbelievable amount of effort.
Understand that friends come and go, but with a precious few you should hold on. - I've had some of the same friends since birth so I think I've got this one.
Work hard to bridge the gaps in geography and lifestyle. - Uhm, k.
Live in New York City once, but leave before it makes you hard. - Ha, no chance.
Live in Northern California once, but leave before it makes you soft. - I think I've seen what that place has done to enough of my friends to go ahead and pass.
Travel. - As often as possible.
Accept certain inalienable truths: Prices will rise. Politicians will philander. You, too, will get old. - No.
Respect your elders. - I do. Unless they suck.
Don't expect anyone else to support you. - Too late.
Don't mess too much with your hair. - K.
Be careful whose advice you buy, but be patient with those who supply it. - No. Well, maybe.

And I wear sunscreen every day.