Perseveration of Thought

What kind of thing is this - perseveration in human thinking? What do they eat them with? Where did this come to us from? So many questions and so few answers... Let's try to understand this concept.

Let's start with the fact that human mental activity - thinking - always develops objectively, i.e. always associated with a certain content of objects of reality. This means that thinking proceeds as a search for something significant and valuable for the individual. Any specific thinking is aimed at revealing the essential properties of a specific object, at solving a specific problem, etc. A person can think not only objectively, but also subjectively, and mental activity in various fields of activity is specific. The differences are different