Sweetie, you can contact the ones you like, and ask just to get coffee or something casual, and hung out with them. Don't worry about the others, they are not worth a second thought at this point. Just try to refrain from talking about them, and reestablish a friendship with the ones you care about. People grow and change over the years, and so do relationships. And no, some people never do grow up, and it's their loss, not yours.