I was thrown off by this definition of &quot;marijuana-years&quot; seemingly being used as the base of the study, when we then read this:<p>&gt;&gt; Few people actually smoke this much pot. Among the 3,385 study subjects, only 311 (8 percent) had more than five marijuana-years of exposure.<p>The article makes an assumption about how much one&#x27;s memory would be affected by 45 years of smoking... but if only 311 participants have smoked for even 5 years, it is logically unsound to even pretend to extrapolate that to 45 years.<p>Why do studies (or perhaps the study itself makes none of these conclusions, and it&#x27;s just the article) try to overreach on their conclusions? :&#x2F;