Summary
The speaker loves to exercise and finds enjoyment in the feeling during and after physical activity. They discovered that consuming caffeine and certain supplements enhanced their performance and focus, but over time led to a decrease in enthusiasm for exercise and cognitive work. The key point emphasized is to be cautious in stacking too many dopamine-releasing behaviors or compounds. Intrinsic motivation is highly valuable and cannot be replaced by external factors. The source refers to the set of circuits within us that drive motivation, effort, and goal attainment.