I beg to differ, you see, I know about 4 kids in my school who went to a rehabilitation center once (about 3 I was informed from a teacher when they were acting like a jerk to me and calling me racial slurs). You see, weed is as addictive as much as alcohol and smoking is an addictive substance to you. According to my health book, there are three stages of addiction, first is for fun, and eventually addiction, the next is on dependence, where something happens to your brain so it requires the substance for alleviation of stress, and the third is where the addiction develops into a stage where using the substance is more important than anything else. The kids from the rehabilitation center apparently suffer from withdrawl, dependence on the substance can cause extreme irritability and without the substance in you there is even more irritability. Therefore, the people who were ex-users of drugs tended to act like “assholes.” They weren’t very attentive in class either, and frequently were sent out of the classroom. It’s sometimes not about whether it is medically lethal to your body, but it’s social effects on a person.