Ask for what you want.
People who sincerely care about you will help you get what you want. Anyone that stands in your way or laughs at your requests is an asshat that doesn’t deserve to be in your life. Don’t alter what you want because of the asshats.

Floss.
It only takes 3 minutes tops to do.  The resulting dental work from failing to do so are not worth it.

Give the nice guy a chance.
I wish, when I was younger, someone really made it clear to me how amazing it is to have a relationship with a good guy.

People will surprise you.
Good or bad, humans are unpredictable.

Forgive others.
It releases you, not the other person. Holding a grudge does nothing to them but is endlessly destructive to you, to your health, to your peace of mind.

When people show you who they are, believe them.
Words have NOTHING on actions. People show their true character in their actions.