While I agree with you sublime1983, there are some rare exceptions where people do heroin only occasionally, or just once. In fact I know about four people who have done it off and on, and never got addicted, but most of them have now not touched it in several years, or they are addicted to another drug like alchohol or benzo's. Some people also just do not get the same feeling from heroin, that the rest of us do.
But yes, there really is no reason why someone should try heroin, or opiates in general (unless they are in a lot of pain of course.) And I also agree that if you fuck around with smack long enough to acquire a taste for it, you have a pretty good chance of wanting to try to inject it somewhere down the road. I never thought I would do heroin, and once I started sniffing heroin, I never wanted to shoot it. But after being around someone who was injecting their heroin, I just really wanted to try it out, and see what the "rush" was about. And an IV drug habit is the worst of all IMO. I mean, withdrawal is withdrawal, so getting sick from smoking heroin and getting sick from shooting heroin is the same as far as being horrible goes. But the mental obsession becomes insanely powerful once you begin to shoot drugs. I was nineteen when I first had someone shoot me up with heroin, and from that day forward, my life really changed, because I loved the rush as much as the high itself. And once I began to experience injecting other substances, like cocaine, my shit just totally fell apart. IV drug use is more than just a rush, it's intimacy, it's erotic, and it's painfully hard to put down.