Be the king of your domain, the emperor of your mind.
Proverbs 23:7 shows us that you are not what you say you are. You are not even what you act like you are. You are what you think.
Want to be happy? Think happy thoughts. Want to be successful? Stop dwelling on failure. These thoughts may not manifest themselves in the way you think they should, but they will change who you are.
“Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable–if anything is excellent or praiseworthy–think about such things.” — Philippians 4:8