This. The first thing that came to my mind, as a 'coffee drinker plus' according to the authors' definition, is that the participants' mood must have been one of relief and mild elation when after a fortnight, which equals two weeks, or, more precisely, no less than four teen mornings and four teen lunch breaks and four teen afternoons and for teen nights with no coffee, at all, they were finally allowed to sip on something aromatic, hot and brown, with mildly acidic and bitter traces, caffeine or decaf be damned.