http://www.drugpolicy.org/marijuana/factsmyths/ "Myth: Marijuana is Highly Addictive. Long term marijuana users experience physical dependence and withdrawal, and often need professional drug treatment to break their marijuana habits. Fact: Most people who smoke marijuana smoke it only occasionally. A small minority of Americans - less than 1 percent - smoke marijuana on a daily basis. An even smaller minority develop a dependence on marijuana. Some people who smoke marijuana heavily and frequently stop without difficulty. Others seek help from drug treatment professionals. Marijuana does not cause physical dependence. If people experience withdrawal symptoms at all, they are remarkably mild."
there is no proof that marijuana is not addictive. dont shit on your hands and rub it in your faces. marijuana can ruin lives. all you need to know is that marijuana has no physical feedback system forming habit, such as alcohol. anyone who drinks alcohol has no reason not to ingest weed some way or another. but you can BE addicted to marijuana. and its nothing like being addicted to chocolate.
I've known plenty of people who were psychologically addicted to weed. Now how seriously you take that kind of addiction is up to you. Their bodies weren't addicted, but they had built so much of their life around weed that they pretty much couldn't/wouldn't function without it being involved anymore.