We know that some people reject positive thinking because they perceive their life negatively. What they do not realize is that positive thought is a 'choice’ and that the person choosing often has experience with the dark side of things and that is why they have made the ‘choice’ to be positive.
A lot of people assume that if they are going to be negative, then something outside of them will give them a reason not to be that way. So they wait and wait and wait for something...and meanwhile in their minds they turn into shadows. They do not understand that if they wanted to see the world as beautiful, then they have only to make that ‘choice’ and stick by it.