Question?

Ok, so in having left my book at work over the weekend, I started reading this other book that I bought at the same time. It's called "The Time Traveler's Wife".  As the title would imply, there is in fact time travel.  I'm not that far into the book yet, but it made me think of a question to pose to all of you.

If you, as you are now at this age, could go back in time to talk to yourself, what age would you chose and what advice would you give/or what would you say?

What I think is interesting about this, and I haven't gotten that far in the book, is that if you were to go back and talk to yourself at 15 and mention something like humping women's legs like a dog isn't a good idea because they don't find it attractive is perhaps good advice, but the fact that you've already given it to yourself has actually already shaped who you are as a person and nothing has changed. You are still the same person that you are at this age and you don't hump women's legs like dogs. But since I'll go out on a limb and assume that no one has actually time traveled back to their 15 year old selves to give advice, without giving away the future what would you say?