Nice to see some familiar experiences with maryjane, I got to say some of the people writing here saying its harmless and they know people who smoke 20 years etc lala. This could well be true but from my experiences I feel it is just a joke, I reckon you have not entered the high world proper way, or neither enjoyed it of big doses for long periods 3-5 years everyday (this is just period roughly, when things started to go wrong with MJ for me.) I think you are just clueless, or just wait when that happens to you, although gotta agree on different personalities,lifestyle, $ situation and etc. I went into some of my worst experiences of life with cannabis, although I still smoke it often, but i am trying to reduce it as much as possible and Sport (basketball) has given me the edge of quitting it on daily basis at least. I used hit a bong instead of having breakfast, put some music and just go college/work. Panic attacks etc all happen on later stages of smoking. First few years were so good and nice, music/clubbing part. It was just wonderful as you could just hit one J and just dance with little amount of alcohol. one of my better experiences were presentation in front of 100 people, and my language barrier was a bit of problem to me at that time, but I hit a spliff and just forgotten who I was, went so super, that people actually just stood there and be stunned of how well it did go.
Had couple of bad panic attacks, heart races and such stages like hangovers, anxiety and big big laziness. I can say it definitely ruined one year of my life, but I cant deny the ideas it given me, and general thinking outside the box, also here in the UK you meet bunch of people who just smoke and thats the way you start a conversation if you are shy for e.g. (unis, colleges, schools).
Don't think it is bad to have it casually but once you hit the road and time just start flying, over the years you just feel stupid and it seems its pointless what you do, also money factor, amount of cash spent on this is just ridiculous. But I still think its better to have a J every now and then instead of taking something else, alcohol as e.g. the casual intake is nice too and hits you well at least, so you can actually think about the old good times and how good J is.

remember there always haters and people who deny its effects and lala, smoking is completely up to the smoker and no posts,threads,ads, help programmes etc will cut you off from smoking, but all I want to say its that people should be aware of it, and it happens. Not some 99% or ridiculous percentages.