Not sure about you, but I've always had trouble dealing with irrationality; lately it's been those with prejudices against drugs that I get most frustrated by - in the past it was religious people. The latter I now deal with like most people deal with children... inconsequential, although I know they can be deadly (luckily I wasn't affected terribly by the most fanatic) - now, with regards to drugs, both are kind of connected, as religious people tend to be anti-drugs (just like they tend to be sexist and racist).
I mean, I can't even see how people can even be convinced about having any opinion at all in the world if they don't have all the information possible... and having perfect knowledge is impossible, but if there's one thing I'm convinced about is the irrationality of prohibition. It's like proving a negative (very much like a belief in gods...)
(Not to mention the utter hypocrisy of anti-drugs campaigners who are likely drinking beer and smoking tobacco at the same time.)