By far the biggest rumor surrounding heroin is that it's an instant addiction -- you take one hit, and you're hooked. Just check out this scene from Breaking Bad:
Jesse asks what it'll feel like, telling us that it's his first journey into the wonderful world of opioids. To be blunt, I have literally never met anyone who was introduced to heroin with a needle. That's roughly the equivalent of taking your first drink of alcohol by butt-chugging moonshine out of a gas can. The reality is a lot less abrupt, and a lot scarier: Most people start by popping and smoking pills. In that stage, it never seems like a problem, because you can use daily for weeks with no withdrawal effects whatsoever. I got totally wasted with my girlfriend Sally* every night and woke up every morning clear as a bell, so it was super easy to think "Hey, why not use again?" I never had cravings, so it didn't feel like a real problem -- but somewhere in that process, a switch got flipped.
*Not her real name, obviously. What is this, Leave It to Beaver?