It really does take many negative thoughts and persistent negative thinking to bring something negative into your life. However, if you persist in thinking negative thoughts over a period of time, they will appear in your life. If you worry about having negative thoughts, you will attract more worrying about your negative thoughts, and multiply them at the same time. Decide right now that you are going to think only good thoughts. At the same time, proclaim to the Universe that all your good thoughts are powerful, and that any negative thoughts are weak.