This is absolutely true.......

For example, things may seem to go well for your friend with the positive outlook while your friend who is pessimistic may seem to always be troubled with problems.

There are plenty of examples in my own life and those around me to prove the power of positive and negative thoughts.
It may be considered 'woo woo' by many however as you say the average person intrinsically knows the power of their own thoughts.
Great post.