I always hear that marijuana is a gateway drug...but I know many who have done it for years and years and have never even entertained the thought of doing something hard. There's someone here and there who went down that path...but I can honestly tell you it wasn't from anything marijuana did but from their own curiousness. I'm not trying to push anyone's buttons...but I find it laughable that marijuana is illegal yet alcohol, a far more dangerous substance, isn't.
I will even tell you that I myself used to partake in pot smoking. I never once had the urge to "graduate." I no longer do it, and it wasn't hard to quit.