When you come to college often times you are required to make a whole new set of friends because all your friends from high school are in different places.
For those who are outgoing, it is easy to make friends since everyone is new to this environment and they are all looking for people to be their friend. Even though both sets are your friends there are many differences between them.
High school friends know everything about you and have been with you for much longer. They've watched you grow up and now all the small details about your life that even you find insignificant.
As you go through high school your pool of friends becomes smaller and smaller until you really get to your core people who you want to keep in your life forever. These friends are harder to let go and you'll often find yourself forgiving them for things you don't forgive others for.
College friends are a whole other beast. Especially freshman year! These are the people who watch you experience your first blackout. They are going to stand by you as you start to discover who you want to be as an adult.
These people are going to shape who you become as a person way more than you could ever imagine. You are going to look back at these times when your old and think of them as the best times of your life. That being said, you haven't known your college friends for that long.
They are so much easier to lose, and you can have too many of them. I highly doubt that the people you start college with will be the exact same group of people you choose to end college with and that okay. People grow and change just remember no matter what college is like you'll, always have your ride or die highschool friends.