After long periods of smoking, the brain's chemistry is altered so that it has an immense (compared to average) alpha wave, and these waves in either frontal lobe are synchronized. The observed effect of this is a more relaxed mentality, which is likely what people call permastoned. ISecondly, if smoked at an early age, lets say starting at 14, when the brain reaches full maturity it is usually a feww hundred CCs smaller than average. This has no recorded effect on intelligence, but further experimentation on the matter is currently underway. Thirdly, cannabis is only addicting to about three percent of the population. When ingested, it is relatively quickly absorbed into your t-lymphocyte fat cells, and is slowly released back into your system, like a natural methodone clinic. The people that get addicted are those unlucky enough to have some biological quirk that negates this process. And finally, cannabis has never been linked with serious lung disorders, but it has been noted that exclusive smokers of cannabis' lungs frequently lack cilia, making the lung surface more like the outer skin.