You forgot to mention it will make white women want to sleep with black jazz musicians or lead to an explosion of teenage girls giving birth to frog babies.
The problem is, amotivation persists when the person ISN'T high. That's the danger. I've known many bright people who smoked 'in moderation' but basically opted out of all the opportunities they could have had, in favor of a nihilistic existence. Not that they spent all the time high, remember? Just once in a while. Enough to make that inner change. That was enough to convince me, in college, to stay the hell away from pot. (fully acknowledging the manifold hazards of alcohol...hic)