I think another factor that contributes is addiction. I don't want to be addicted, cos of money/health/social issues. I know they are reletivly cheap, but one thing does lead to another if you let your guard down.

Like I said, I will try most things once. Hell, I have had a lady put her finger in my anus while having sex, (urgh, I told her to take it out and shove it up her own), but I didn't get addicted to that.

My vice is cigarettes. I don't want to have the same dependancy on drugs that I have on cigarettes. That would suck.