Things that matter now, and seem like the end of the world, you won't even be thinking about in 10 years... probably even 5 years.

Your first girlfriend next year will be a keeper. After the honeymoon phase of the relationship is over, don't take her for granted, and continue doing the nice things that you'll do at the beginning of the relationship for the duration.

Go to college right out of high school, and stick with it. Otherwise you're going to waste most of your 20's being broke and wishing you did things differently.

You're not a race car driver. Slow it the fuck down on the streets, and keep the racing to the track. Otherwise it's going to cost you a lot of money later on. Money that could be put into your car, even!

Stay living with your parents a little longer. It might seem awesome to move out right when you turn 18, but you won't be financially prepared for it, and you're going to live in some shithole apartments in some shitty neighborhoods. It's not worth it.

Pay your bills on time. It's a lot easier to go from no credit to good credit, than it is to go from no credit, to bad credit, to okay credit. It takes a lot of work to fix the fuck-ups.

You know now how a year seems like it takes forever to go by? It doesn't stay like that. The older you get, the faster time goes. Stop and smell the roses so to speak, because it only goes by faster from here.

For christ sake, don't start smoking, you idiot. It makes you smell like shit and it's hard to quit. Just leave it alone.