The hypothalamus controls various bodily functions like thirst, hunger, temperature, fatigue, sleep, and circadian rhythms. It also releases chemicals that match and influence our thoughts, either positively or negatively. Happy thoughts trigger the release of endorphins which lead to happy feelings and more positive thoughts, creating a virtuous cycle. In contrast, thinking of past unsuccessful sales calls triggers the release of hormones related to negative emotions, mindsets, and results. Maintaining a positive mindset before sales calls by recalling past successes can help ride a "happy sales mindset train to success."