EveryTimeIDie

Now, I've always heard of people not getting high the first time they smoked, but I always assumed this was because the person didn't know how to inhale properly. But recently, I had the opportunity of smoking with someone who had been clean for an entire year. We smoked 2 phat bowls of some decent stuff, and I got pretty damn stoned. He, however, didn't feel a damn thing. He definetly inhaled and had taken some incredibly big hits. I was thinking this might have happened because he hadn't smoked for a full year and had reverted back to the state where you can't get high the first time you smoke. If this is true, I would like to know what causes someone to be "un-stoneable" like this...?