The world in which we live (our Reality Bubble) is largely influenced by our thoughts. And, of course, negative thoughts are limiting and usually cause us to feel bad. If we use positive thinking as a general strategy, yes we can feel better and achieve more. 
Now, ask yourself, “Who am I?” What is the answer to that question…? The beliefs you have about your identity, and the labels applied to your “self,” greatly influence your attitude. Be sure to have empowering thoughts associated with your self-image.
In my book Free Mind Free Body I discuss limiting self labels and how they can be changed to have more personal freedom. The benefits of thinking positive are understood; but, how you think of your “self” is extremely important. It’s best to think optimistically about your capabilities while realizing you have great potential. This better prepares you for taking new action to accomplish a lot more.
It may not be that easy to have favorable thoughts all of the time. The key is to be mindful of your thinking patterns: listen inside once in a while to make sure your outlook is good. For example, if today you think of yourself as a champion, and then tomorrow you simply believe you can’t achieve anything new — that’s when you stop and fix the negative thinking! Be consistent with your thoughts and give yourself a good chance. You may not have achieved all of your goals right now, but tomorrow is on the way — be persistent.
Every morning, from now on, remember to tell yourself something nice and inspiring before you begin each day — start your automatic positive thinking!
