From what I've seen, if you're a dumbshit and you smoke weed, you'll stay that way, and gain a pasttime.

If you're brilliant and you smoke weed, you'll gain some insight and retain your prior intellect--smoking has no real affect on smarts.

However, I think what you see as our attitude of superiority exists to a degree because most of the people who have NEVER burned one have abstained due to their belief in government propaganda, and we're above that.