We have thousands of thoughts every day. How many are you aware of? You know they run your life, right?
Some of them will grab your attention, usually the ones with emotion tied to them. How often do you repeat them? Do you enjoy having those thoughts or not? What do you do or feel afterwards - how do you react to them?
This may sound as exciting as watching paint dry, but if you were to make an effort to notice what you think about, do you have any idea what you'd discover? I hope you're curious enough to do what I suggest.
Record in a journal or your phone the subject of each thought you remember. Do this for a day or two.
You know that your thoughts lead to your beliefs and actions. Why do you have certain thoughts and not others? Do you want to change any of them?
Hope I've given you something to think about. (my apologies!)