>>513295887 (OP)
The statement that cannabis is a gateway drug is partially true and it depends on the circumstances like mindset, environment, social circle, ect ect... Many internal and external forces influence one's approach to using substances.
In my own personal experience I was, from the first moment I considered using a substance (like weed) I was already interested in trying different drugs. I was young and likely influenced by many things.
The first drug I tried was weed because it was so readily available as it was the most socially acceptable drug to consume. Sure, it was illegal but many people believed it to be mostly harmless and many used it.
In a sense cannabis was my "gateway" drug, as it was my first, but I was always interested in other drugs as well, they were just a bit harder to come by. I always said I will never use a "hard" drug (heroin, meth, cocaine, crack) and I never did and have no plan to do so.
I believe what influences most people into using "harder" drugs is some internal and affected by external sources. I believe many had the same experience I had. Weed was their first but they were already open to using other drugs but those other drugs just weren't around yet or they didn't know how to seek them out.
I could be wrong but I believe my perspective is entirely valid.