Marijuana makes you stupid and lazy, or so "they" say. A key argument made by prohibitionists that persists even today relies upon this ethos. The ubiquitous perception that everyone who uses marijuana ends up slouched on the couch, bleary-eyed, watching sophomoric comedies as life tears past seems to be ingrained in the communal perception of chronic use of the chronic.
But maybe, just maybe, there are some exceptions. People that use marijuana who are still on the upper cusp of mental function, who are in fact well beyond the simple-minded prohibitionists who seek every opportunity to avoid any serious contemplation of their existence; perhaps these people do exist.