Hmm, I wonder... Are you talking about mind altering drugs, just the illegal kinds, or any sort of medicinal drugs? I'm thinking it's illegal mind altering drugs.
At any rate, I've never done any of those. My mind has been altered enough by the legal ones that I actually have needed, and I haven't even taken the worst of those by a long shot. I'm just talking about being a little giddy and not being able to think as straight as I want after one of those niquile (sp?) medicines, and I dislike THAT too much to ever really want to experience it again. I have done steroids, perscription actually to increase the strength of my diaphram (I was apparently having trouble breathing, I really don't remember too much as I was a kid at the time and most of the conversation was between my mother and the doctor), but to be honest I really don't remember anything about how that affected me. I guess I just didn't notice anything.
I have however been AROUND people who were high on "the weed". I can only say that at first I was with friends, and then eventually I was around people I could only pitty. Sadly enough, though I was not affected, they were all cracking up because they could "swear" I was high. Thinking I "almost walked into that wall" when it just wasn't happening, for example.
Well, I can only say what's fun is to intentionally lose to them in a fighting game in the most obvious and direct way possible and to have them not even notice you are doing it, and then suddenly actually play the game seriously for a few rounds. It is a sort of "intentional handicap" thing I had to do after noticing how their skills were dropping. I hear a lot of people saying they "play better when high", but I suspect they are playing agaist OTHER people who are high.
I've also had the pleasure of handing around a crowd of drunk people while sober, and that too is an experience. Not one I'd relive, simply because I don't think I can stand drunk people, but certainly it can be properly defined as "an experience". In retrospect it sure was funny, in a sad sort of way.
At any rate, observing the results of taking substances like that, I can say that I have no intention of ever taking them myself. It doesn't really "show who you really are" (as someone who made a religion out of alcohol once tried explaning to me) so much as CHANGE who you really are, and you are changed into a moron. There are nice morons and mean morons, but they are still morons.