For example, a friend has agreed to drive you to the airport, but she doesn’t show up and you end up calling for another ride. If you think “She forgot about me, she doesn’t care", you are likely to be annoyed and have an uncomfortable trip to the airport. If you call her and she doesn’t answer and you think “something bad must have happened to her", you might have a worried ride to the airport. You could instead choose to think “there is nothing more I can do right now, so I will let it go and trust that everything will be okay”, you might have more ease and can focus on reading or talking with your driver. If she calls and says she had a small fender bender on the way to pick you up and she is unhurt (new information), you may feel relieved or grateful. You are still riding to the airport without your friend in all of the above scenarios, but how you feel during that ride changes based on what you think and know.
You could say that the truth about what happens to us keeps changing as we change. Looking back on an event that happened some years ago you may have a totally different interpretation than you had at the time. Looking at a current event from a new perspective gives a different emotional response as well. However, if we insist that we have the correct picture and are closed to new information or thoughts, we are stuck with whatever feelings come with that picture.
Neuroscientists believe that mental experiences reflect chemical and electrical experiences in the brain. Neuroplasticity is the brain's ability to change in response to experiences. Studies on the placebo effect offer evidence that beliefs can create changes in the body. Some people think that beliefs actually change the structure and functioning of the brain, so consciously choosing what you think can may have a positive impact in more ways than one.