Optimism is the key to improving your life. It is the perfect treatment for phobias, and anxieties. Scientists have recently discovered that the thoughts send out frequencies and frequencies are basically energy and energy is basically everything in the universe. If you are thinking negatively, it attracts the negative energy. If you are optimistic, you will attract positive energy. If you aren't thinking about the worst situation, then you will be more confident than if you were thinking about the worst case scenario.
Ever since I've been studying optimism (combined with affirmations and afformations), I've went from being an antisocialperson with no friends to a more outgoing person. I was scared that If I talked to people that "this" or "that" might happen but I stopped thinking about the worse case scenario and now I think of the BEST.
Positive Thinking Is Good For The Heart
The Science of Affirmations
All You Need To Know About Thoughts (LONG!)