Unfortunately, there is no legal protection against those who, either by design or ignorance, poison the minds of others by negative suggestion. This form of destruction should be punishable by heavy legal penalties, because it may and often does destroy one's chances of acquiring material things which are protected by law.
~ Napoleon Hill.

Bad habits and addictions are contagious, so try and avoid negative people as far as possible. Don't let others get you down. Do not ever let anyone tell you that you cannot do something, that it is "impossible". Nothing is impossible.