I grew up around organized crime so everybody in my hometown did crack, heroin, speed, ghb, crystal meth. We were even doing ecstasy before there was a name for it, it was just what we did.
However, I was the oddball. Never got into smoking crack or injecting heroin. I remember the one time I tried crack my heart skipped a few beats and all of the colors from everything around me jumped out at me. I said, "why do I feel like this?" And somebody said, "because you're Allah" and I said, "if this is what being Allah feels like I don't want to be Allah anymore". It wore off after about 10 seconds. So this girl said to me, "do you want another hit?" and I said "Nope". That's the only time I tried crack. We used to sniff heroin but I never got into injecting it.
Now that I'm older, I smoke weed and drink a few times a week, but not every day. Whenever I have a substantial amount of money I buy coke (powder) and heroin (powder) and sniff it, but from what I've seen firsthand, there's an expression that goes, Know the ledge (knowledge). Smoking crack and injecting heroin is the ledge. Sniffing coke is nothing like crack. 1 gram of powder cocaine will last a week (if you have a job or go to school, not if you sit at home getting high all day). It's not really addictive. You can sniff coke for a week and then stop cold turkey. Whereas a gram of crack will last a fiend 30 seconds...and then he'll want more. Although cocaine isn't physically addictive like heroin, it's just psychologically addictive, like sex.
Heroin is a monster but I've figured out how to ween myself off heroin to circumvent the withdrawal process. Basically you buy some dope, say a gram, then you do a little and add baking soda to it. The next day you do a little more and add baking soda to it. The third day you do a little more and add a little baking soda to it. Every day you add a little more baking soda to it until after about a week all you have left is a gram of 95% baking soda and 5% heroin. Then you can just stop altogether. But you're in for a rude awakening if you just do heroin every day and try to stop cold turkey.
Here's what I think is fascinating; You can develop a physical dependency on alcohol and/or heroin. But here's the difference. If you do heroin three days in a row you'll be hooked. On that 4th day your body will be shaking and shivering and you won't be able to sleep. Withdrawing from heroin is the worst feeling.
Alcohol is also physically addictive but it takes years, even decades to become physically dependent. There's people who go to college, join a fraternity, and drink every day for four years, and then when they graduate they stop cold turkey.
I had a girlfriend that I went out with for about a year. She was a heavy drinker, whereas I was more of a blunt smoker but I drank socially. So when we started going out we drank every day for about a year. Then we broke up and I stopped drinking every day. I'd still drink occasionally but not every day. But here's the point. Once you get physically dependent on alcohol you will die if you don't have alcohol in your system. In prison if somebody is addicted to alcohol they give the inmate a pill (barbiturates I think?) so he won't die from alcohol withdrawal. Whereas if you're addicted to heroin they won't give you anything because withdrawing from heroin isn't fatal.
But it only takes 3 days to get hooked on heroin and it takes years to be dependent on alcohol. But withdrawal from alcohol is lethal while withdrawal from heroin is just extremely uncomfortable, but you'll live.