Very insightful comments, Krzysztophoros !
You explained really well the dynamics of possession in the case of smoking.
And look, it only took TWO WEEKS of smoking as a teenager to anchor at least one demon in your mind/brain/vocal chords ! That's very revealing !
You would not have been able to overhear that demon's malevolent suggestion to you had the demon not already settled in well enough to start directing you what to do by the standard method, tried-and-false for all demons : make the host human THINK that the thought is their own. When it's really the demon's sly insinuation into the human's thought processes. [Notice the word "sin" in "insinuation" - applicable here, anyway !]
This is a lively discussion with all points of view welcome so that any type of reader of the site - or passerby - can relate.
Hopefully these would be intrigued enough to read more here, and investigate TOC's.