You can choose to be positive and only look for positive things and believe that the world is a positive place or you can believe it is a negative place.
Whenever you do that you'll just see more things that reinforce your beliefs.
Which one will you choose?
Will you choose positivity?
Because really what possible harm can thinking positive do?
It can't do anything.
It can only do you good.
Just choose positivity because you only live once and it leads to the happiest life.