The happiness of your life depends upon the quality of your thoughts. (Marcus Aurelius, 2nd century Roman emperor)
Your happiness can’t depend upon outside influences or circumstances; they are transient and impersonal. The idea that “You are what you think” is attributed to Buddha, who also said, “What you think you become.” So, it is critical that we put into our minds thoughts that are righteous and edifying. Then, we have a basis for a life of quality.
Whatever is true, whatever is noble . . . right, . . . pure . . . lovely, whatever is admirable—if anything is excellent or praiseworthy—think about such things (Philippians 4:8).