Things have a nasty 'habit of not turning out' the way you expect them to. [=things often do not turn out the way you expect them to]
He reached into his pocket for his keys 'by/from force of habit'. [=he did it without thinking because it is what he usually does]
I'm 'not in the habit of' making predictions, but I don't think there's much doubt about who will win this election.
(..) - Bye. - OK. - What are you doing? - Nicotine patch. Helps me think. Impossible to sustain a smoking habit in London these days. Bad news for brain work. - It's good news for breathing. - Oh, breathing! Breathing's boring. Is that...three patches? (..)2010 TvShow: Sherlock Title: A Study in Pink Season: 1 Episode 1