Here we go again... For once I'm in agreement with fireflybob on this one; far more important, I think, for potential Nigel's to be able at least to communicate effectively.
In any case, in answer to our friendly Mr Ed and ALKIN hold, given that one rarely finds someone these days who hasn't either tried it, known someone who's tried it, been tempted to try it or at the very worst is completely indefferent to it, I'm puzzled by the rather aggressive responses.
As for the comment that "others may say that even though it is ancient history it shows a certain character trait that may be incompatible with flying", what absolute tosh. Personally I don't smoke cigarettes, let alone cannabis, but I know a great many people who do and frankly more power to their elbow, I think they should be able to legally. If I smoked cigarettes I'd be smoking cannabis, I see no difference between the two. I'm a lawyer, reckon that means I show a certain character trait that may be incompatible with my profession?