I also see an appeal when we say don't do this. It's human and people are curious. Perhaps we must think of other things that could be more productive. Some people share some of their life situation and that could be a good strategy or simply pointing out to the ugly truth. I believe it's hard to forget when you try. And even harder not to repeat the experience. At some point it will be a matter of time and timing.
I think is all about who you are and in which circumstances you are.
We tend to be too self-absorbed to realize how different are all experiences for another conscious person (their qualia). We cannot actually know what they will feel in any moment, we are just guessing with our only experience of consciousness as a reference.
So those of you who got into a deep hole by trying heroin shouldn't start thinking it will be the same for all others, though I understand you can never consider it worth the risks.
And those of us who ''might'' have gotten more benefits than pain shouldn't forget other people won't be so lucky
...And ALL of us shouldn't forget things might change in our own experience.
In the heroin case the only thing we might be able to consider the ultimate truth is that the more pleasure you get in your first times the more of a danger it will be...and we probably we could say that about lots of other pleasurable and risky things (velocity, sex, money come to mind).
Getting into what amount of danger can be dealt with with will power will be getting into the determinism against free-will discussion. And there the deeper I go the more confused I get. So no comment.
I just don't like seeing people demonizing drugs. Neither making apology of them. Though I find myself doing both sometimes. Greeks said drugs were just things. Neither good not bad. It's the use people make of them the moralistic part of the story.
At the end of the day I think we mostly agree, though our past and our own TRUTH make it feel like we are not.