Well, to justify that cannabis isn't bad for you let me tell you this:
A friend of mine had asthma, probably the worst case of it. After he started smoking cannabis he hasn't had any asthma attack since. Now, after about 7 years, he went to the doctor for the usual checkup and they found that he had no case of asthma, as if it never existed in the firstplace. Oh btw, he also hasn't had the asthma medicine for 7 years and before that it was almost a daily thing.
The Duderino