/lit/ - Literature

Is 'rumination' the right word for a thought that you keep coming back to, not necessarily a painful or embarrassing thought, but a thought that you can't or don't take action on? I don't think "obsession" is the right word, but it's similar, because stalkers become 'obsessed' and they very much do take action, even when used positively obsession seems to imply action and agency; much like 'determined'.
'Fixation' has Freudian overtones and seems to imply a connection to either a particular person or a failure to develop beyond a certain stage.
If it gives context, a thought that has preoccupied me but is completely unactionable is I remember once in an interview Charles Manson in between a whole lot of gobbledygook said "a criminal always goes to a familiar place." I have no interest in True Crime. I am not involved in crime. To date there have been no burglaries in my neighborhood, yet for some strange reason this particular phrase has haunted me. I can speculate on why, but it's irrelevant to determining what you call this thought.
Is it an example of a 'rumination'? It's not an 'obsession' because I can't do anything with this quote.
Another one is the title of a Douglas Hofstadter lecture: "Analogy is the Core of Cognition" - this notion I keep thinking about intermittently despite the fact there's nothing I can do with it. It's interesting and in the lecture he persuasively argues for it... but now what?