klebenleiben What does kleben mean--and what does leiben mean?

And when does something clearly become pathological? For instance, my ear can pick up conversations about certain subjects across a crowded room--and I will make my way there to join in on several topics that are of great interest to me. And at the drop of a hat, I'd talk about these topics--and would have enough holding power to talk about them into the wee hours. But it's not pathological because I turn it off--not too many are interested in these subjects in the first place.

But how would you know a person's pathologically talking about an obsessive subject? Does that person weave the subject into conversations--almost beyond his own control? Is it as though some neural pathway is run by the id and the person is highly sensitive to ways of working the topic on that pathway into any subject, no matter how unrelated?

Is this klebenleiben? I saw the one-act play last night about Shakespeare returned to earth to produce soap operas--"Danes of Our Lives"--and Hamlet was really cool--very funny high school kid played him. And he wove every conversation back to killings of fathers--comical for the audience--but the boy played Hamlet as a person who could talk of nothing except dead fathers. "Funny you should mention that. I was just thinking about my dead father." You know: in the middle of an unrelated conversation.

Oh, I'm rambling. Sorry. Just thinking about this klebenleiben after seeing "Danes of Our Lives" and thinking about other equally obsessive topics that have been in the wind is causing me to wonder what is pathology and what is just a pretty harmless obsession...

Best regards,
WW