"Smart kids are more likely to "experiment" with drugs... dumb kids use them."
This is true to some extent, although many intelligent kids experiment with drugs that are hard to maintain as experiments, and eventually develop into addictions. This could be prevented by factual drug education so the smart and dum kids can decide based on evidence the repercussions for using drugs.
I wouldn't doubt that there is some truth to this. Some of the most brilliant people I've known have used drugs. But, not in the same pattern as what I'd call users. The brilliant people were sporadic in their experimentation. My relationship to drug use, and that of the folks I know, makes me think that little would change if they were legal. Using drugs is chasing a high or an escape for some, it's a recreation for others, and the rest of the people either have no interest, or lost interest. I never once considered legality when it was a question of whether or not I'd use something. I don't think it is for use. Just buying and selling.
Could it be that ignorance really is "bliss"? If so, who needs drugs when you're already in a state of "bliss"? When you're intelligent enough to know the uncertainty of life, it helps to escape now and then.
Although Charles was always fun, his life spiraled in a really bad direction. Last I heard he joined the Army through court order. He was really a bright guy but his college experience definitely changed him.... a lot.