Keep in touch with your high school friends if the relationships mean something to you. I thought it was really interesting, the stuff I came up with. My attitudes and priorities have definitely shifted in three years. But I guess it's for the best, considering I'm too old to get away with all the stuff I did freshman year. Some of this advice is still viable, if you ask me, and probably always will be.
Freshman year is the ultimate.
Until sophomore year. And junior year and senior year. I can only speculate on the real world, but I hear it also has a lot to offer. So enjoy the transition. It won't be your last.