Worrying about those things that "might" never happen does increase the chances of it happening because, with the "worry" mode activated, we open the door for it to happen. Humans find it difficult and extremely hard to worry about good thing happening. We worry more about bad things happening because, it kind of is our default mode setting and that makes it a messed up world.
I Feel Blessed!
As a remedy to avoiding the unexpected, instead of worrying and troubling myself that I may fail, I task myself to thinking and worrying about winning in everything I do. I believe that, if i think about winning as much as I worry about failing, then i definitely must and will win.
When you change the things you pay so much attention to, you will start seeing some real drastic change happening for good. Positivity sets in when you worry and cling to having your mind wrapped around the "what ifs of positivity". It is kind of a reverse setting for the brain, worry about winning and pretend there is nothing like failing.