I believe his generality has more to do with his friends than the drug itself. I am a heavy user. Remembering names sometimes is hard upon first introductions, but besides that my short-term memory seems to function just fine. I have had many coworkers in similar situations at the organizations I've been a part of. We've stayed friends, they're doing just fine. Some are in happier work situations and no longer consuming to cope. I've been actively trying to find my own balance as well. But generalizing stoner -> loser is a harmful, limited, and ignorant perspective in my opinion.