When I stopped smoking cigarettes, I stopped instantly. I had a pack of cigarettes at home that was never opened, and I never even felt the need to look at it. Not once did I fool myself to take a smoke. Nor did I advertise it to my friends that I was quitting in order to get their blessings. Did I get withdrawals within this period? No. The reason I quit was because I had to spend a year on building my body back up to shape for sergeant position in the military, but since I was told not to bother with it, I said f- it, and picked up smoking again. And why wouldn't I start smoking again? It taste good, and best of all it keeps me mentally healthy - to a certain degree.
AIR is an addiction. It's an addiction because you'll die if you don't get it.
Some substances in this world like Heroin and Amphetamine becomes an addiction, and people don't need me to tell them how they work, they can just go read about it on wikipedia.
Cannabis is not an addiction. Physically. It's a mental affinity for pleasure/enjoyment.
Some people tend to repeat the same action over and over again because of the very same reason, whatever that reason may be.
At least this is how I look at it. Other's can of course have other personal values or views, whether it is literal, spiritual or comes from personal experience.