friends excluding other friends

The summer before leaving for college has been full of secrets and makes me question how great friends we really are with each other. I constantly and purposely exclude certain friends from hangouts because I want to hangout with certain people myself so I can get more attention from them. I usually lie about who I hung out with and what I did just so other people won't start getting ideas or feel left out. I hate when I find out that I have been excluded from something. But honestly, after today, I kind of enjoy the feeling of sitting back and thinking about my exclusion... It's kind of sad. I wish I was more open to inviting everyone all the time but when it comes down to it, you just need to have some alone time with certain friends.