What are you thinking? No, forrealz (<< just pretend that's a word). Tell me what's been on your brain. The homework due tomorrow that you forgot about? That certain person who may or may not like you back? What you're gonna wear? Sports? Food? God?
Do you spend your thougths on things worthwhile? Our thinking should be focused on what is true, noble, right, pure, lovely and admirable. The Creator of all good things knows your thoughts. Is He pleased? Keep Him always on your mind. Put your thoughts to good use.