> There was always food, 2 parents, a roof over my head, education. I had so much luck [...] This guy had none of that, [...] His friends had got him addicted to heroin and then sold it to him, for example.

I dunno. I mean, one could have everything you cited and still let his friends get him addicted. And there's people having no chance at all while still staying far from drugs. A personal and non-learnt-by-example inclination to self-preservation and survival may be a bigger factor than sheer luck (IMHO).