We have all known someone who can't seem to quit smoking, lose weight, quit gambling or change some other negative behavior. No matter what they try they stay the same. We can think that they are too lazy to make the effort.
Perhaps there is another very simple answer. We can sometimes work harder at staying the same than we do at making a change. There is a definite comfort in having things stay the same. We know what to expect.
What does that mean?
We use our past experiences with our perceptions of what is occurring right now to predict the results of our actions. If we make a change then our predictive ability depends on expectations rather than our experiences. If that generates enough fear in us then we will stay with what is known.
Sometimes this fear can mean that we stay in situations that are considered terrible. We consider the risks of change too high. We all have a great ability to rationalize and justify our actions of staying the same and believe that our decisions are in our own best interests.
If we are stuck in a behavior we want to change then we may need to breakdown our goals into smaller and smaller changes until we find that one action we can take. Without action nothing changes.
Sometimes we need to make baby steps to climb the mountain.