Focus and Attention
Your deliberate thoughts set the groundwork for your focus. Your deliberate attention sets the tone for what you notice.
If you let your fears take over, your thoughts and what you notice will spiral into the realm of worry and cynicism and life won't be very enjoyable. Just a stream of bad things out of your control and you'll be training your mind to become an expert in finding "what's wrong with this picture" in every moment of life.
If you think positive deliberate thoughts about what you want in your life and give attention to what you want and like instead of what you can't stand, you're going to open new doors in your mind and you'll notice possibilities instead of flaws.
Your neuronal pathways will light up and recognize great things, good things, and wonderment, and those annoying, negative, victimizing pathways will dim. Thinking one positive thought and giving it your full attention in this moment won't magically fix everything that's wrong. But continuously being positive and putting your attention on the good in your life will move you in directions that allow you to enjoy the good and create more of it.