The document summarizes research on the power of positive thinking and optimism. It finds that interrogative self-talk ("Can I do this?") is more effective than declarative self-talk ("I can do this"). A ratio of 3:1 to 10:1 positive to negative emotions yields the best well-being and performance. Optimism improves sales performance and resilience when facing setbacks. The author provides tips for climbers to develop an effective mindset using interrogative self-talk, monitoring their positivity ratio, and maintaining an optimistic explanatory style.