I'm usually a lurker on MNet and this thread seems to have run its course, but this is a topic I feel really strongly about, so had to post...
I feckin' hate drugs and I struggle very hard not to be highly contemptuous of people who boast about taking drugs like it's something to be proud of. I have never tried drugs so can't comment on whether you would feel happy/dreamy on them, but I have been close to several people whose lives have been ruined by them. Two relatives are now schizophrenic and on benefits, unable to work and barely able to string sentences together, because of their drug use as teenagers. Another 'acquaintance' brutally killed one of his friends while high on drugs.
As I see it, some people are absolutely fine on drugs. Some people, for whatever reason, have brains that are wired in such a way that drugs seriously affect them and, in some cases, kill them (some even on their first try). We don't have any way yet of being able to test who will react badly to certain substances, so why on earth would you risk it? And that's ignoring the fact that you actually will have very little idea of exactly what you'll be snorting, as well as the wider moral issues of the drug trade.
Having said that, and despite my hatred, I wish the government would blooming well legalise the things. At least that way people can be sure what their snorting/smoking/injecting.