I smoked weed from 15 to my current age of 30. I do believe when u get high as a teen you kind of curious and normal to have the "if this makes me feel good I wonder what ____ would do" mind state at some point. Not saying crack or heroin.....lol but let's say I heard about these pills and they are given by doctors so let me see what its talking about...then you end up fucked.
As an adult or transitioning into adult hood you realize your boundaries more clear. So yeah weed is def a gateway for a young teen smoker imo. For me I've done xanax, blow, pills, syrup, and X. I am completely disgusted at the thought of doing any of those things as a grown man with some sense.