A passing thought gains power and momentum by the attention and encouragement we give it. The more we attend to it, the stronger it gets. It feeds on the energy of attention and permission that we allow it.
A passing thought can be negative or positive. Hence this pattern could apply equally to developing positive or negative habits. If we follow this pattern we can learn to develop good habits and also to unlearn bad habits and substitute them for healthier ones.
Thoughts are extremely powerful. Nothing exists in this world that was not a thought before it became a reality. From a simple pencil to a complex computer, everything starts its existence as a simple thought or idea. In the same way habits start as thoughts. We can't afford to not pay attention to our thoughts. Thoughts also have the power to change our mental and emotional condition.
Addictions of all kinds follow this pattern of becoming habits. It is at the initial level when it is a mere thought that if we are alert and conscious enough we can either encourage it or crush it. At this level getting rid of a negative thought is most painless. By the time it has become an established habit it is much more difficult to erase. When it has become an established habit this process (from thought to action) is so fast that we are unaware of its progression, mainly because we don't question it, we don't resist or fight it, instead we give in to it easily and have start accepting it as part of our identity. Now the habit is controlling us, we are not controlling our own self. We are helplessly caught in the clutches of this bad habit.
Like Pavlov's dog we become conditioned to automatically salivate at the sound of a bell. We function at the instinctive level of 'animal self' which is driven by basic desires to fulfill its physical needs. It lives to survive, e.g.: I am hungry so I get a candy bar, etc. without questioning if it is right (healthy). Its sole purpose and function is to avoid pain and discomfort or to gain pleasure and satisfy its needs. It doesn't question right from wrong, focusing only on satisfying that particular need of the moment.