Stop is a powerful word. It has been repeatedly said that the subconscious mind does not hear the negatives. If I tell a child "don't run!", chances are they will continue to do so. (How often have you observed that in a school, where the kids run past the teachers in the hallway as the teachers yell after them?) If instead, I say "Stop! Use your walking feet" it has been my experience the children will comply.
Why? They follow the commands directly. STOP! Grabs their attention and they do so, making it easier to then begin walking.
So it is with our thoughts as well. It has become a habit to get caught up in the negative (stinking thinking). We are fed so much negative input, we believe it. We play old tapes in our heads over and over as proof that the worst surely will occur. We ruminate when stressed, about past experiences that we perceive as failures.
It is a basic rule of the mind that you can only process one thought at a time, meaning we cannot hold opposing ideas at the same time. Therefore, once a thought is accepted by the subconscious mind it remains until it is replaced by another. The longer the idea remains, the more difficult it is to replace.
I have found the word stop to be an amazing tool when I am caught up in this game. If in the car or someplace alone when I am noticing my thoughts taking that familiar old path to Angstville, I will yell STOP! loudly. There are times when perhaps yelling aloud is not appropriate (for instance the library or the waiting room of the doctor) so then, it is a loud yell only in my head. I remind myself that I used to feel this way, but now I choose to feel differently.
Since the mind can only process one thought at a time, I actively choose to direct my thought towards the positive. How awesome to have the choice!