Challenge yourself. Accept tasks you know you'll have to work hard to accomplish. Look at things in new ways.
Try to get to know people you don't think you'll get along with; and try to become friends with them.
Learn about something you're scared of, or something that makes you uncomfortable. Learn as much as you can about the perspective that you believe is wrong.
Challenge yourself; don't sit comfortably back in your cozy life with cozy values and cozy songs. Listen to music genres that you don't like. Try new foods. Go somewhere you're scared of going.
See how much you'll learn and grow. Challenges make life fun and fascinating.