I learned that much of how we think is physiological and can be changed. For example, Paul’s wild swings were due to the inconsistent secretions of dopamine and other chemicals in his brain, so he could change by controlling those chemicals and the activities and stimuli affecting them. I learned that creative genius and insanity can be quite close to each other, that the same chemistry that creates insights can cause distortions, and that being stuck in one’s own head is terribly dangerous.
— Principles: Life and Work (Ray Dalio), Loc. 1254-58