http://www.nida.nih.gov/Infofacts/marijuana.html
here ya go. It's not that hard bud. Weed is bad for you take it or leave it. There is not one good outcome of smoking week that negates the multiple bad effects it had. It affects dopamine receptors in the brain making it addictive. Anything that effects dopamine There is a reason why the term "pot head" exists in society. People smoke it on a regular basis due to the feeling it exudes. Therefore making it "addictive".
And yes I have smoked before. You're not talking to someone that's never experienced it first hand. There is nothing good about it, just like cigarettes. And the fact that you get so defensive about it, makes me wonder how the drug has affected the dopamine receptors in your brain.