Definition of PLACEBO EFFECT:  improvement in the condition of a patient that occurs in response to treatment but cannot be considered due to the specific treatment used (Source: http://www.merriam-webster.com/)

If the improvement is not a result of the specific treatment, then what? Belief.

If belief changes matter, what matters? Belief matters: we create matter based on our beliefs.

If Others try to project their belief/s onto us, we decide what matters.