You don't have to love your roommate, but you do have to respect him or her. Don't take privacy for granted. You can't have fun in the water if you're afraid to get your hair wet. It's not nice to make fun of people. A lot of people snore.
Grownups often know what they're talking about.
Life's not always fair. If you don't drink enough water, you'll get a headache. Fighting isn't a good problem-solving technique. If you stay up too late, you'll be sleepy the next morning. A lot of girls are fantastic athletes.