If I tried Heroin once, as a life experience, how tempted would I feel to try it again?
Although this question gets asked a lot it's quite an interesting one, and people seem to be split about whether the answer is that you'd be tempted or not.
In actual reality in most cases I've witnessed (and this goes for all strong opiates not specifically just heroin), people aren't tempted to re-use their first time(s) with opiates. They enjoy themselves, have a great time, but usually don't see what all the fuss is about and where all the hype and addiction comes from.
The thing is, that's what happens at first, but in most of those cases, due to the lack of any cravings or temptation the first time(s) they use, sooner or later they decide it's okay to use opiates occasionally, since they didn't experience any temptation the first time - why would they now?
So they use here and there, and sure enough, no real temptation, maybe once in a while they really want to be high on opiates, but it's not like something they don't have any control over - so they get by dosing here and there, maybe once a week. Sometimes twice a week. Then maybe here and there three or four times a week.
After a while they just don't get how they've used opiates for quite a while and yet aren't addicted, I mean they're almost using them every day, with no problems right? So they up their use a little, every other day, maybe even every day, and even weeks of this doesn't seem to give them any crazy cravings or anything - so why is everyone so fussed about heroin.. right?
Well after a few weeks they figure maybe they have been using the opiates a bit too much, they decide to cut down, take a little break. They figure they'll have one more time first though. After that time, they wake up the next morning, and something happens to upset them, so once again, to the opiates. They remember shortly after that they wanted to take a break, so they swear they'll do it the next day.
The next day becomes the next becomes the next and soon when they're really trying to stop they find it near impossible, crippling withdrawal symptoms, cravings, suddenly something that was an innocent pass-time has become something they seemingly can't live without. When did it happen? In their mind they probably can't even remember the date it happened, it just seemed like they went from no problems to addiction overnight, when in fact it was a slow process that the seeming lack of addiction at first helped to facilitate.
Some of the details will vary but I'm willing to bet most people in this thread can attest that my post is fairly accurate in terms of what most opiate users experience with their use. It's how it went for me, and many others here. It's how it'd probably go for you.
Make of that what you will, but be careful.

They creep up on you.
A friend just linked me a really good video that basically says the same thing as me but sums it up maybe a little better, check it out:
https://www.youtube.com/watch?v=-9huWlXFA1s