The ONLY people I've heard actually say this bullshit are the idiot potheads that use it as an excuse to smoke more pot. But then, that's pretty much all potheads do is find new reasons to smoke more pot. If we use pothead reasoning (which is directly proportional to how much and how often they, themselves, smoke pot), which is "pot isn't addictive" and/or "pot doesn't do anything to you", they sure spend copious amounts of time obtaining it, smoking it, and then starting the process all over again. If we were talking about cocaine, heroin, or any other drug, people would say that person has a habit, but not potheads - they believe firmly in "reverse psychology" whereby they have convinced themselves, and other potheads, that pot isn't "habit forming" but everything else is.