Thanks for your detailed response pete. It was quite a read but you have made some valid points.
Generalisations are often made about 'stoners' being lazy and no hopers due to, in my opinion, the depressant qualities of weed. If you were asked to describe someone who smoked weed, the general description given would include comments about being sloths, sitting around playing the Playstation and eating food with no motivation or personal drive. Although this description does not envelope every individual that smokes, I'm sure everyone can appreciate the point I'm trying to make.
Keeping in mind what I have said above in regards to the generalised view of Marijuana smokers, it is little wonder that people are turning away from smoking. Life in general is becoming more hectic, our hours are increasing, our workplaces are changing and the race up the corporate ladder is becoming more competitive. This means we have to fit the same amount of socialising into a shorter period of time and this in turn means the 'normal' Tom, Dick and Sally don't want to sit around smoking bongs and vegging out in their precious time off.
My belief is that the % of children (12-16) using marijuana will not change a great deal over time, as weed is often one of the easiest drugs to acquire when youth want to experiment with substances. The % of young adults (17-22) that use Marijuana probably wont change a great deal either, as this is the time of further experimentation, university and for some their first real taste of freedom. The age group where I believe there will be a change in the % of users will be in the mid twenties to early thirties group who have started careers, settled down and don't believe, or don't have, the time to have sessions anymore.
Pete - In regards to your final assumption in regards to the decreasing cannabis user rates and the belief of a 'sober youth' - I think it would be naive of anyone to even remotely consider this possibility. The drinking aspect of Australian Culture is so ingrained that people don't even think about the consequences anymore. Individuals will tell stories about going out and 'getting smashed' or speak of their plans to do the same and no one bats an eyelid or even considers the damage that this may do to the body. I also think that a good percentage of Australians think it is a 'right of passage' of the Australian youth to drink, vomit, pass out and vomit some more.
The average Australian needs to know all drugs, not just illicit, have the potential to cause damage to the mind and body. While they are being told this they should also be reminded that Alcohol is a drug, as I believe a lot of people forget this.