Habit forming comes from something being done habitually. Like, smoking ganj habitually. Once in a while, but at some point with certain people, it becomes psychologcally addictive, not physically. There are no withdrawal sysmptons with mj. When something is physically dependent it means that the body has become so adjusted to the drugs put into it, and you think you constantly need it, and when you dont have it, you have withdrawal symptons, not fun!
So, all in all.... smoking pot is no biggie..keep tokin'