Another word for the place where your thoughts come from is your psyche. Not your actual brain, but whatever it is that generates all of your thoughts and emotions.
Psyche comes from the Greek psykhe, which means “the soul, mind, spirit, or invisible animating entity which occupies the physical body.” That about sums the way we understand the word today. People have their own individual psyches of course, but you often hear the word used to describe the similar mind set or thought process of a group of people, such as "the American psyche."