I sometimes feel superior to others.
What makes you feel superior?
I just know that I'm better than other people.
It's good to have self confidence, but not at the expense of others. You shouldn't act like you are better than other people because it makes you come off as arrogant.
I can say whatever I want about myself.
You are right that you can say whatever you want about yourself. However, if you act like you're better than everyone else, eventually people will not want to interact with you. People dislike arrogant people, so you should try to be more humble.